GPG linux command manual

gpg(1)                                                                     gpg(1)



NAME
       gpg -- encryption and signing tool

SYNOPSIS
       gpg  [--homedir name]  [--options file]  [options]  command  [args]

DESCRIPTION
       gpg is the main program for the GnuPG system.


       This man page only lists the commands and options available.  For more
       verbose documentation get the GNU Privacy Handbook (GPH) or one of the
       other documents at http://www.gnupg.org/docs.html .

       Please  remember  that option parsing stops as soon as a non option is
       encountered, you can explicitly stop option parsing by using the  spe-
       cial option "--".

COMMANDS
       gpg recognizes these commands:

       -s, --sign
                 Make   a  signature.  This  command  may  be  combined  with
                 --encrypt.

       --clearsign
                 Make a clear text signature.

       -b, --detach-sign
                 Make a detached signature.

       -e, --encrypt
                 Encrypt data. This option may be combined with --sign.

       -c, --symmetric
                 Encrypt with a symmetric cipher  using  a  passphrase.   The
                 default  symmetric  cipher  used is CAST5, but may be chosen
                 with the --cipher-algo option.

       --store   Store only (make a simple RFC1991 packet).

       --decrypt [file]
                 Decrypt file (or stdin if no file is specified) and write it
                 to  stdout  (or  the  file  specified with --output). If the
                 decrypted file is signed, the signature  is  also  verified.
                 This command differs from the default operation, as it never
                 writes to the filename which is included in the file and  it
                 rejects files which don't begin with an encrypted message.

       --verify [[sigfile]  [signed-files]]
                 Assume  that  sigfile  is  a signature and verify it without
                 generating any output.       With no arguments,  the  signa-
                 ture packet is read from stdin.  If only a sigfile is given,
                 it may be a complete signature or a detached  signature,  in
                 which  case  the  signed stuff is expected in a file without
                 the ".sig" or ".asc" extension.  With more than 1  argument,
                 the  first  should be a detached signature and the remaining
                 files are the signed stuff.  To read the signed  stuff  from
                 stdin, use - as the second filename.  For security reasons a
                 detached signature cannot  read  the  signed  material  from
                 stdin without denoting it in the above way.

       --verify-files [files]
                 This is a special version of the --verify command which does
                 not work with detached signatures.  The command expects  the
                 files to be verified either on the command line or reads the
                 filenames from stdin;  each name must be on  separate  line.
                 The command is intended for quick checking of many files.

       --encrypt-files [files]
                 This is a special version of the --encrypt command. The com-
                 mand expects the files to be encrypted either on the command
                 line or reads the filenames from stdin; each name must be on
                 separate line. The command is intended for a  quick  encryp-
                 tion of multiple files.

       --decrypt-files [files]
                 The  same  as --encrypt-files with the difference that files
                 will be decrypted. The syntax or the filenames is the  same.

       --list-keys [names]

       --list-public-keys [names]
                 List  all  keys  from  the public keyrings, or just the ones
                 given on the command line.

                 Avoid using the output of this command in scripts  or  other
                 programs  as  it  is likely to change as GnuPG changes.  See
                 --with-colons for a machine-parseable  key  listing  command
                 that is appropriate for use in scripts and other programs.

       --list-secret-keys [names]
                 List  all  keys  from  the secret keyrings, or just the ones
                 given on the command line.  A '#' after  the  letters  'sec'
                 means  that the secret key is not usable (for example, if it
                 was created via --export-secret-subkeys).

       --list-sigs [names]
                 Same as --list-keys, but the signatures are listed too.

                 For each  signature  listed,  there  are  several  flags  in
                 between  the  "sig"  tag  and keyid.  These flags give addi-
                 tional information  about  each  signature.   From  left  to
                 right,  they are the numbers 1-3 for certificate check level
                 (see --default-cert-check-level), "L" for a  local  or  non-
                 exportable signature (see --lsign-key), "R" for a nonRevoca-
                 ble signature (see --nrsign-key), "P" for a  signature  that
                 contains  a  policy  URL  (see --cert-policy-url), "N" for a
                 signature that contains a  notation  (see  --cert-notation),
                 and "X" for an eXpired signature (see --ask-cert-expire).

       --check-sigs [names]
                 Same as --list-sigs, but the signatures are verified.

       --fingerprint [names]
                 List all keys with their fingerprints. This is the same out-
                 put as --list-keys but with the additional output of a  line
                 with  the fingerprint. May also be combined with --list-sigs
                 or --check-sigs.  If this command is given twice,  the  fin-
                 gerprints of all secondary keys are listed too.

       --list-packets
                 List only the sequence of packets. This is mainly useful for
                 debugging.

       --gen-key Generate a new key pair. This command is normally only  used
                 interactively.

                 There  is an experimental feature which allows you to create
                 keys in batch mode. See the file doc/DETAILS in  the  source
                 distribution on how to use this.

       --edit-key name
                 Present  a  menu  which  enables  you  to do all key related
                 tasks:

                 sign      Make a signature on key of user name If the key is
                           not  yet  signed by the default user (or the users
                           given with -u), the program displays the  informa-
                           tion  of  the key again, together with its finger-
                           print and asks whether it should be  signed.  This
                           question  is repeated for all users specified with
                           -u.

                 lsign     Same as --sign but the signature is marked as non-
                           exportable  and  will  therefore  never be used by
                           others.  This may be used to make keys valid  only
                           in the local environment.

                 nrsign    Same as --sign but the signature is marked as non-
                           revocable and can therefore never be revoked.

                 nrlsign   Combines the functionality of nrsign and lsign  to
                           make  a  signature  that is both non-revocable and
                           non-exportable.

                 revsig    Revoke a signature.  For every signature which has
                           been  generated  by  one of the secret keys, GnuPG
                           asks whether a revocation  certificate  should  be
                           generated.

                 trust     Change  the  owner  trust  value. This updates the
                           trust-db immediately and no save is required.

                 disable

                 enable    Disable or enable an entire key.  A  disabled  key
                           can not normally be used for encryption.

                 adduid    Create an alternate user id.

                 addphoto  Create  a  photographic user id.  This will prompt
                           for a JPEG file that will  be  embedded  into  the
                           user  ID.   A very large JPEG will make for a very
                           large key.

                 deluid    Delete a user id.

                 revuid    Revoke a user id.

                 addkey    Add a subkey to this key.

                 delkey    Remove a subkey.

                 addrevoker
                           Add a designated revoker.  This takes one optional
                           argument: "sensitive".  If a designated revoker is
                           marked as sensitive, it will not  be  exported  by
                           default (see export-options).

                 revkey    Revoke a subkey.

                 expire    Change  the  key  expiration time.  If a subkey is
                           selected, the expiration time of this subkey  will
                           be changed.  With no selection, the key expiration
                           of the primary key is changed.

                 passwd    Change the passphrase of the secret key.

                 primary   Flag the current  user  id  as  the  primary  one,
                           removes  the  primary  user id flag from all other
                           user ids and sets the timestamp  of  all  affected
                           self-signatures  one second ahead.  Note that set-
                           ting a photo user ID as primary makes  it  primary
                           over  other  photo user IDs, and setting a regular
                           user ID as primary makes  it  primary  over  other
                           regular user IDs.

                 uid n     Toggle  selection  of user id with index n.  Use 0
                           to deselect all.

                 key n     Toggle selection of subkey with index n.  Use 0 to
                           deselect all.

                 check     Check all selected user ids.

                 showphoto Display the selected photographic user id.

                 pref      List  preferences from the selected user ID.  This
                           shows the actual  preferences,  without  including
                           any implied preferences.

                 showpref  More  verbose preferences listing for the selected
                           user ID.  This shows the preferences in effect  by
                           including   the   implied   preferences   of  3DES
                           (cipher), SHA-1 (digest), and  Uncompressed  (com-
                           pression)  if they are not already included in the
                           preference list.

                 setpref string
                           Set the list of user  ID  preferences  to  string,
                           this should be a string similar to the one printed
                           by "pref".  Using an empty  string  will  set  the
                           default  preference  string, using "none" will set
                           the preferences to nil.  Use "gpg -v --version" to
                           get  a list of available algorithms.  This command
                           just initializes an internal  list  and  does  not
                           change  anything  unless  another command (such as
                           "updpref") which changes  the  self-signatures  is
                           used.

                 updpref   Change the preferences of all user IDs (or just of
                           the selected ones to the current list  of  prefer-
                           ences.   The timestamp of all affected self-signa-
                           tures will be advanced by one second.   Note  that
                           while   you  can  change  the  preferences  on  an
                           attribute user ID (aka "photo ID"), GnuPG does not
                           select  keys via attribute user IDs so these pref-
                           erences will not be used by GnuPG.

                 toggle    Toggle between public and secret key listing.

                 save      Save all changes to the key rings and quit.

                 quit      Quit the program without updating the key rings.

                 The listing shows you the key with its  secondary  keys  and
                 all  user ids. Selected keys or user ids are indicated by an
                 asterisk. The trust value is displayed with the primary key:
                 the  first is the assigned owner trust and the second is the
                 calculated trust value.  Letters are used for the values:

                 -         No ownertrust assigned / not yet calculated.

                 e         Trust calculation has failed; probably due  to  an
                           expired key.

                 q         Not enough information for calculation.

                 n         Never trust this key.

                 m         Marginally trusted.

                 f         Fully trusted.

                 u         Ultimately trusted.

       --sign-key name
                 Signs  a public key with your secret key. This is a shortcut
                 version of the subcommand "sign" from --edit.

       --lsign-key name
                 Signs a public key with your secret key but marks it as non-
                 exportable.   This  is  a shortcut version of the subcommand
                 "lsign" from --edit.

       --nrsign-key name
                 Signs a public key with your secret key but marks it as non-
                 revocable.   This  is  a  shortcut version of the subcommand
                 "nrsign" from --edit.

       --delete-key name
                 Remove key from the public keyring.  In  batch  mode  either
                 --yes  is  required  or the key must be specified by finger-
                 print.  This is a safeguard against accidental  deletion  of
                 multiple keys.

       --delete-secret-key name
                 Remove key from the secret and public keyring. In batch mode
                 the key must be specified by fingerprint.

       --delete-secret-and-public-key name
                 Same as --delete-key, but if a secret key exists, it will be
                 removed  first.  In  batch mode the key must be specified by
                 fingerprint.

       --gen-revoke name
                 Generate a revocation certificate for the complete  key.  To
                 revoke a subkey or a signature, use the --edit command.

       --desig-revoke name
                 Generate  a  designated  revocation  certificate  for a key.
                 This allows a user (with the permission of the keyholder) to
                 revoke someone else's key.

       --export [names]
                 Either  export  all keys from all keyrings (default keyrings
                 and those registered via option --keyring), or if  at  least
                 one  name is given, those of the given name. The new keyring
                 is written to stdout or to the file given with option  "out-
                 put".  Use together with --armor to mail those keys.

       --send-keys [names]
                 Same  as --export but sends the keys to a keyserver.  Option
                 --keyserver must be used to give the name of this keyserver.
                 Don't  send  your  complete  keyring to a keyserver - select
                 only those keys which are new or changed by you.

       --export-secret-keys [names]

       --export-secret-subkeys [names]
                 Same as --export, but exports the secret keys instead.  This
                 is normally not very useful and a security risk.  The second
                 form of the command has the special property to  render  the
                 secret part of the primary key useless; this is a GNU exten-
                 sion  to  OpenPGP  and  other  implementations  can  not  be
                 expected to successfully import such a key.

                 See  the  option  --simple-sk-checksum if you want to import
                 such an exported key with an older OpenPGP implementation.

       --import [files]

       --fast-import [files]
                 Import/merge keys. This adds the given keys to the  keyring.
                 The fast version is currently just a synonym.

                 There are a few other options which control how this command
                 works.  Most notable here is the --merge-only  option  which
                 does  not  insert  new keys but does only the merging of new
                 signatures, user-IDs and subkeys.

       --recv-keys key IDs
                 Import the keys with the given key  IDs  from  a  keyserver.
                 Option  --keyserver  must  be  used to give the name of this
                 keyserver.

       --refresh-keys key IDs
                 Request updates from a keyserver for keys that already exist
                 on  the  local  keyring.   This is useful for updating a key
                 with the latest signatures, user IDs,  etc.   Option  --key-
                 server must be used to give the name of this keyserver.

       --search-keys [names]
                 Search  the  keyserver  for the given names.  Multiple names
                 given here will be joined  together  to  create  the  search
                 string  for  the keyserver.  Option --keyserver must be used
                 to give the name of this keyserver.

       --update-trustdb
                 Do trust database maintenance.  This command  iterates  over
                 all keys and builds the Web-of-Trust. This is an interactive
                 command because it may have to ask for the "ownertrust" val-
                 ues for keys.  The user has to give an estimation of how far
                 she trusts the owner of the displayed key to correctly  cer-
                 tify  (sign) other keys.  GnuPG only asks for the ownertrust
                 value if it has not yet been assigned to a key.   Using  the
                 --edit-key  menu,  the  assigned value can be changed at any
                 time.

       --check-trustdb
                 Do trust  database  maintenance  without  user  interaction.
                 From time to time the trust database must be updated so that
                 expired keys or signatures and the resulting changes in  the
                 Web-of-Trust can be tracked.  Normally, GnuPG will calculate
                 when this is required and do it automatically  unless  --no-
                 auto-check-trustdb  is  set.   This  command  can be used to
                 force a trust database check at any time.  The processing is
                 identical to that of --update-trustdb but it skips keys with
                 a not yet defined "ownertrust".

                 For use with cron jobs, this command can  be  used  together
                 with  --batch in which case the trust database check is done
                 only if a check is needed.  To force a  run  even  in  batch
                 mode add the option --yes.

       --export-ownertrust
                 Send  the  ownertrust  values to stdout.  This is useful for
                 backup purposes as these values  are  the  only  ones  which
                 can't be re-created from a corrupted trust DB.

       --import-ownertrust [files]
                 Update  the  trustdb  with  the  ownertrust values stored in
                 files (or stdin if not given); existing values will be over-
                 written.

       --rebuild-keydb-caches
                 When  updating  from  version  1.0.6  to  1.0.7 this command
                 should be used to create signature caches  in  the  keyring.
                 It might be handy in other situations too.

       --print-md algo [files]

       --print-mds [files]
                 Print  message  digest of algorithm ALGO for all given files
                 or stdin.  With the second form  (or  a  deprecated  "*"  as
                 algo) digests for all available algorithms are printed.

       --gen-random 0|1|2                 [count]
                 Emit COUNT random bytes of the given quality level. If count
                 is not given or zero, an endless sequence  of  random  bytes
                 will  be emitted.  PLEASE, don't use this command unless you
                 know what you are doing; it may remove precious entropy from
                 the system!

       --gen-prime mode                  bits             [qbits]
                 Use the source, Luke :-). The output format is still subject
                 to change.

       --version Print version information along with  a  list  of  supported
                 algorithms.

       --warranty
                 Print warranty information.

       -h, --help
                 Print  usage  information.   This is a really long list even
                 though it doesn't list all options.  For every option,  con-
                 sult this manual.

OPTIONS
       Long    options   can   be   put   in   an   options   file   (default
       "~/.gnupg/gpg.conf").  Short option names will not work - for example,
       "armor"  is a valid option for the options file, while "a" is not.  Do
       not write the 2 dashes, but simply the name  of  the  option  and  any
       required  arguments.   Lines with a hash ('#') as the first non-white-
       space character are ignored.  Commands may be put in  this  file  too,
       but that is not generally useful as the command will execute automati-
       cally with every execution of gpg.

       gpg recognizes these options:

       -a, --armor
                 Create ASCII armored output.

       -o, --output file
                 Write output to file.

       --mangle-dos-filenames

       --no-mangle-dos-filenames
                 The Windows version of GnuPG replaces the  extension  of  an
                 output  filename to avoid problems with filenames containing
                 more than one dot.  This is not necessary for newer  Windows
                 versions  and  so  --no-mangle-dos-filenames  can be used to
                 switch this feature off and have GnuPG append the new exten-
                 sion.  This option has no effect on non-Windows platforms.

       -u, --local-user name
                 Use  name  as  the  user  ID  to  sign with.  This option is
                 silently ignored for the list commands, so that  it  can  be
                 used in an options file.

       --default-key name
                 Use  name as default user ID for signatures.  If this is not
                 used the default user ID is the first user ID found  in  the
                 secret keyring.

       -r, --recipient name

                 Encrypt  for  user id name. If this option is not specified,
                 GnuPG asks for the  user-id  unless  --default-recipient  is
                 given

       --default-recipient name
                 Use  name  as default recipient if option --recipient is not
                 used and don't ask if this is a valid one. name must be non-
                 empty.

       --default-recipient-self
                 Use the default key as default recipient if option --recipi-
                 ent is not used and don't ask if this is a  valid  one.  The
                 default  key is the first one from the secret keyring or the
                 one set with --default-key.

       --no-default-recipient
                 Reset --default-recipient and --default-recipient-self.

       --encrypt-to name
                 Same as --recipient but this one is intended for use in  the
                 options  file  and  may  be used with your own user-id as an
                 "encrypt-to-self".  These keys are only used when there  are
                 other  recipients  given  either by use of --recipient or by
                 the asked user id.  No trust checking is performed for these
                 user ids and even disabled keys can be used.

       --no-encrypt-to
                 Disable the use of all --encrypt-to keys.

       -v, --verbose
                 Give  more information during processing. If used twice, the
                 input data is listed in detail.

       -q, --quiet
                 Try to be as quiet as possible.

       -z n, --compress-level n
                 Set compression level to n. A value of 0 for n disables com-
                 pression. Default is to use the default compression level of
                 zlib (normally 6).

       -t, --textmode

       --no-textmode
                 Use  canonical  text  mode.   --no-textmode  disables   this
                 option.   If  -t  (but not --textmode) is used together with
                 armoring and signing,  this  enables  clearsigned  messages.
                 This  kludge  is  needed for command-line compatibility with
                 command-line versions of PGP; normally you would use  --sign
                 or --clearsign to select the type of the signature.

       -n, --dry-run
                 Don't make any changes (this is not completely implemented).

       -i, --interactive
                 Prompt before overwriting any files.

       --batch

       --no-batch
                 Use batch mode.  Never ask, do not  allow  interactive  com-
                 mands.  --no-batch disables this option.

       --no-tty  Make sure that the TTY (terminal) is never used for any out-
                 put.  This option is needed  in  some  cases  because  GnuPG
                 sometimes prints warnings to the TTY if --batch is used.

       --yes     Assume "yes" on most questions.

       --no      Assume "no" on most questions.

       --default-cert-check-level n
                 The default to use for the check level when signing a key.

                 0 means you make no particular claim as to how carefully you
                 verified the key.

                 1 means you believe the key  is  owned  by  the  person  who
                 claims  to  own  it but you could not, or did not verify the
                 key at all.  This is useful for  a  "persona"  verification,
                 where you sign the key of a pseudonymous user.

                 2  means  you did casual verification of the key.  For exam-
                 ple, this could mean that you verified that the key  finger-
                 print and checked the user ID on the key against a photo ID.

                 3 means you did extensive  verification  of  the  key.   For
                 example,  this  could mean that you verified the key finger-
                 print with the owner of the key  in  person,  and  that  you
                 checked,  by  means of a hard to forge document with a photo
                 ID (such as a passport) that  the  name  of  the  key  owner
                 matches the name in the user ID on the key, and finally that
                 you verified (by exchange of email) that the  email  address
                 on the key belongs to the key owner.

                 Note  that  the  examples given above for levels 2 and 3 are
                 just that: examples.  In the end, it is up to you to  decide
                 just what "casual" and "extensive" mean to you.

                 This option defaults to 0.

       --trusted-key long key ID
                 Assume  that  the  specified  key  (which must be given as a
                 full 8 byte key ID) is as trustworthy as  one  of  your  own
                 secret keys. This option is useful if you don't want to keep
                 your secret keys (or one of them) online but still  want  to
                 be able to check the validity of a given recipient's or sig-
                 nator's key.

       --trust-model classic|always
                 Set what trust model GnuPG should follow.  The models are:


                 classic   This is the regular web-of-trust as  used  in  PGP
                           and GnuPG.

                 always    Skip  key validation and assume that used keys are
                           always fully trusted.  You won't use  this  unless
                           you   have   installed  some  external  validation
                           scheme.  This option also suppresses the  "[uncer-
                           tain]"  tag  printed  with  signature  checks when
                           there is no evidence that the user ID is bound  to
                           the key.

       --always-trust
                 Identical  to '--trust-model always'.  This option is depre-
                 cated.

       --keyserver name
                 Use name as your keyserver.  This is the server that --recv-
                 keys,  --send-keys,  and --search-keys will communicate with
                 to receive keys from, send keys to, and search for keys  on.
                 The  format  of  the  name  is a URI: 'scheme:[//]keyserver-
                 name[:port]' The scheme is the type of keyserver: "hkp"  for
                 the HTTP (or compatible) keyservers, "ldap" for the NAI LDAP
                 keyserver, or "mailto" for the Graff email keyserver.   Note
                 that  your  particular  installation of GnuPG may have other
                 keyserver types available as well.   Keyserver  schemes  are
                 case-insensitive.

                 Most  keyservers  synchronize  with  each other, so there is
                 generally no need to send keys to more than one server.  The
                 keyserver  "hkp://subkeys.pgp.net"  uses  round robin DNS to
                 give a different keyserver each time you use it.

       --keyserver-options parameters
                 This is a space or comma delimited string that gives options
                 for the keyserver.  Options can be prepended with a 'no-' to
                 give the opposite meaning.  Valid import-options or  export-
                 options  may  be  used  here  as  well to apply to importing
                 (--recv-key) or exporting (--send-key) a  key  from  a  key-
                 server.   While  not  all options are available for all key-
                 server types, some common options are:

                 include-revoked
                           When  searching  for  a  key  with  --search-keys,
                           include  keys  that are marked on the keyserver as
                           revoked.  Note that this option is always set when
                           using  the  NAI  HKP  keyserver, as this keyserver
                           does not differentiate between revoked  and  unre-
                           voked keys.

                 include-disabled
                           When  searching  for  a  key  with  --search-keys,
                           include keys that are marked on the  keyserver  as
                           disabled.   Note that this option is not used with
                           HKP keyservers.

                 include-subkeys
                           When receiving a key, include subkeys as potential
                           targets.   Note  that this option is not used with
                           HKP keyservers, as they do not support  retrieving
                           keys by subkey id.

                 use-temp-files
                           On  most  Unix-like  platforms, GnuPG communicates
                           with the keyserver helper program via pipes, which
                           is  the most efficient method.  This option forces
                           GnuPG to use temporary files to  communicate.   On
                           some  platforms  (such as Win32 and RISC OS), this
                           option is always enabled.

                 keep-temp-files
                           If using 'use-temp-files', do not delete the  temp
                           files  after using them.  This option is useful to
                           learn  the  keyserver  communication  protocol  by
                           reading the temporary files.

                 verbose   Tell  the keyserver helper program to be more ver-
                           bose.  This option can be repeated multiple  times
                           to increase the verbosity level.

                 honor-http-proxy
                           For keyserver schemes that use HTTP (such as HKP),
                           try to access the keyserver  over  the  proxy  set
                           with the environment variable "http_proxy".

                 auto-key-retrieve
                           This  option  enables  the automatic retrieving of
                           keys from a keyserver  when  verifying  signatures
                           made by keys that are not on the local keyring.

                           Note  that  this  option  makes  a  "web bug" like
                           behavior possible.  Keyserver  operators  can  see
                           which  keys  you request, so by sending you a mes-
                           sage signed by a brand new key  (which  you  natu-
                           rally  will  not  have on your local keyring), the
                           operator can tell both your  IP  address  and  the
                           time when you verified the signature.

       --import-options parameters
                 This is a space or comma delimited string that gives options
                 for importing keys.  Options can be prepended with  a  'no-'
                 to give the opposite meaning.  The options are:

                 allow-local-sigs
                           Allow  importing key signatures marked as "local".
                           This is  not  generally  useful  unless  a  shared
                           keyring scheme is being used.  Defaults to no.

                 repair-pks-subkey-bug
                           During import, attempt to repair the damage caused
                           by the PKS keyserver bug (pre version 0.9.6)  that
                           mangles  keys  with  multiple  subkeys.  Note that
                           this cannot completely repair the damaged  key  as
                           some crucial data is removed by the keyserver, but
                           it  does  at  least  give  you  back  one  subkey.
                           Defaults to no for regular --import and to yes for
                           keyserver --recv-keys.

       --export-options parameters
                 This is a space or comma delimited string that gives options
                 for  exporting  keys.  Options can be prepended with a 'no-'
                 to give the opposite meaning.  The options are:

                 include-non-rfc
                           Include non-RFC  compliant  keys  in  the  export.
                           Defaults to yes.

                 include-local-sigs
                           Allow  exporting key signatures marked as "local".
                           This is  not  generally  useful  unless  a  shared
                           keyring scheme is being used.  Defaults to no.

                 include-attributes
                           Include  attribute  user  IDs  (photo  IDs)  while
                           exporting.  This is useful to export keys if  they
                           are  going  to  be used by an OpenPGP program that
                           does not accept attribute user IDs.   Defaults  to
                           yes.

                 include-sensitive-revkeys
                           Include  designated  revoker  information that was
                           marked as "sensitive".  Defaults to no.

       --show-photos

       --no-show-photos
                 Causes --list-keys, --list-sigs, --list-public-keys, --list-
                 secret-keys,  and  verifying a signature to also display the
                 photo ID attached to the key, if  any.   See  also  --photo-
                 viewer.  --no-show-photos disables this option.

       --photo-viewer string
                 This  is the command line that should be run to view a photo
                 ID.  "%i" will be expanded  to  a  filename  containing  the
                 photo.   "%I"  does  the  same,  except the file will not be
                 deleted once the viewer exits.  Other flags are "%k" for the
                 key  ID,  "%K" for the long key ID, "%f" for the key finger-
                 print, "%t" for  the  extension  of  the  image  type  (e.g.
                 "jpg"),   "%T"   for  the  MIME  type  of  the  image  (e.g.
                 "image/jpeg"), and "%%" for an actual percent sign.  If nei-
                 ther  %i  or %I are present, then the photo will be supplied
                 to the viewer on standard input.

                 The default viewer is "xloadimage -fork -quiet -title 'KeyID
                 0x%k' stdin".  Note that if your image viewer program is not
                 secure, then executing  it  from  GnuPG  does  not  make  it
                 secure.

       --exec-path string
                 Sets  a  list of directories to search for photo viewers and
                 keyserver helpers.  If not provided, keyserver  helpers  use
                 the compiled-in default directory, and photo viewers use the
                 $PATH environment variable.

       --show-keyring
                 Causes --list-keys, --list-public-keys,  and  --list-secret-
                 keys  to display the name of the keyring a given key resides
                 on. This is only useful when you're listing a  specific  key
                 or set of keys. It has no effect when listing all keys.

       --keyring file
                 Add  file  to  the  list of keyrings.  If file begins with a
                 tilde and a slash, these are replaced by the HOME directory.
                 If  the  filename does not contain a slash, it is assumed to
                 be in the GnuPG home directory ("~/.gnupg" if  --homedir  is
                 not used).  The filename may be prefixed with a scheme:

                 "gnupg-ring:" is the default one.

                 It  might  make  sense to use it together with --no-default-
                 keyring.

       --secret-keyring file
                 Same as --keyring but for the secret keyrings.

       --trustdb-name file
                 Use file instead of the default  trustdb.   If  file  begins
                 with  a  tilde  and  a slash, these are replaced by the HOME
                 directory. If the filename does not contain a slash,  it  is
                 assumed  to  be  in  the GnuPG home directory ("~/.gnupg" if
                 --homedir is not used).

       --homedir directory
                 Set the name of the home  directory  to  directory  If  this
                 option  is  not  used it defaults to "~/.gnupg". It does not
                 make sense to use this in a options file.  This  also  over-
                 rides the environment variable "GNUPGHOME".

       --charset name
                 Set  the  name of the native character set.  This is used to
                 convert some strings  to  proper  UTF-8  encoding.  If  this
                 option  is not used, the default character set is determined
                 from the current locale.  A verbosity level of 3  shows  the
                 used one.  Valid values for name are:

                 iso-8859-1
                           This is the Latin 1 set.

                 iso-8859-2
                           The Latin 2 set.

                 iso-8859-15
                           This is currently an alias for the Latin 1 set.

                 koi8-r    The usual Russian set (rfc1489).

                 utf-8     Bypass  all  translations  and  assume that the OS
                           uses native UTF-8 encoding.

       --utf8-strings

       --no-utf8-strings
                 Assume that the arguments are already given as UTF8 strings.
                 The  default (--no-utf8-strings) is to assume that arguments
                 are encoded in the character set as specified by  --charset.
                 These  options affect all following arguments.  Both options
                 may be used multiple times.

       --options file
                 Read options from file and do not try to read them from  the
                 default  options  file  in the homedir (see --homedir). This
                 option is ignored if used in an options file.

       --no-options
                 Shortcut for "--options /dev/null".  This option is detected
                 before an attempt to open an option file.  Using this option
                 will also prevent the creation of a "~./gnupg" homedir.

       --load-extension name
                 Load an extension module. If name does not contain  a  slash
                 it  is  searched  for in the directory configured when GnuPG
                 was built  (generally  "/usr/local/lib/gnupg").   Extensions
                 are not generally useful anymore, and the use of this option
                 is deprecated.

       --debug flags
                 Set debugging flags. All flags are or-ed and  flags  may  be
                 given in C syntax (e.g. 0x0042).

       --debug-all
                 Set all useful debugging flags.

       --enable-progress-filter
                 Enable  certain PROGRESS status outputs.  This option allows
                 frontends to display a progress indicator while gpg is  pro-
                 cessing  larger  files.  There is a slight performance over-
                 head using it.

       --status-fd n
                 Write special status strings to the file descriptor n.   See
                 the file DETAILS in the documentation for a listing of them.

       --logger-fd n
                 Write log output to file descriptor n and not to stderr.

       --attribute-fd n
                 Write attribute subpackets to the file descriptor  n.   This
                 is  most  useful  for use with --status-fd, since the status
                 messages are needed to separate out the  various  subpackets
                 from the stream delivered to the file descriptor.

       --sk-comments

       --no-sk-comments
                 Include  secret  key  comment  packets when exporting secret
                 keys.  This is a GnuPG extension to  the  OpenPGP  standard,
                 and is off by default.  Please note that this has nothing to
                 do with the comments in clear text signatures or armor head-
                 ers.  --no-sk-comments disables this option.

       --no-comment
                 See  --no-sk-comments.  This option is deprecated and may be
                 removed soon.

       --comment string
                 Use string as the comment string in clear  text  signatures.
                 The default behavior is not to use a comment string.

       --default-comment
                 Force  to  write  the  standard comment string in clear text
                 signatures.  Use this to overwrite a --comment from a config
                 file.   This  option  is  now  obsolete  because there is no
                 default comment string anymore.

       --emit-version

       --no-emit-version
                 Force inclusion of the version string in ASCII armored  out-
                 put.  --no-emit-version disables this option.

       --sig-notation name=value

       --cert-notation name=value

       -N, --set-notation name=value
                 Put the name value pair into the signature as notation data.
                 name must consist only of printable  characters  or  spaces,
                 and  must  contain a '@' character.  This is to help prevent
                 pollution of the  IETF  reserved  notation  namespace.   The
                 --expert  flag  overrides the encoded in UTF8, so you should
                 check that your --charset is set correctly.  If  you  prefix
                 name with an exclamation mark (!), the notation data will be
                 flagged as critical (rfc2440:5.2.3.15).  --sig-notation sets
                 a  notation  for  data  signatures.   --cert-notation sets a
                 notation for key signatures  (certifications).   --set-nota-
                 tion sets both.

                 There  are special codes that may be used in notation names.
                 "%k" will be expanded into the  key  ID  of  the  key  being
                 signed,  "%K"  into the long key ID of the key being signed,
                 "%f" into the fingerprint of the key being signed, "%s" into
                 the  key  ID  of the key making the signature, "%S" into the
                 long key ID of the key making the signature, "%g"  into  the
                 fingerprint  of the key making the signature (which might be
                 a subkey), "%p" into the fingerprint of the primary  key  of
                 the  key  making the signature, and "%%" results in a single
                 "%".  %k, %K, and %f are only meaningful when making  a  key
                 signature (certification).

       --show-notation

       --no-show-notation
                 Show  signature notations in the --list-sigs or --check-sigs
                 listings as well as when verifying a signature with a  nota-
                 tion in it.  --no-show-notation disables this option.

       --sig-policy-url string

       --cert-policy-url string

       --set-policy-url string
                 Use  string as Policy URL for signatures (rfc2440:5.2.3.19).
                 If you prefix it with an exclamation mark  (!),  the  policy
                 URL  packet  will  be flagged as critical.  --sig-policy-url
                 sets a a policy url for data signatures.   --cert-policy-url
                 sets  a  policy  url  for  key  signatures (certifications).
                 --set-policy-url sets both.

                 The same %-expandos used for  notation  data  are  available
                 here as well.

       --show-policy-url

       --no-show-policy-url
                 Show policy URLs in the --list-sigs or --check-sigs listings
                 as well as when verifying a signature with a policy  URL  in
                 it.  --no-show-policy-url disables this option.

       --set-filename string
                 Use  string as the filename which is stored inside messages.
                 This overrides the default, which is to use the actual file-
                 name of the file being encrypted.

       --for-your-eyes-only

       --no-for-your-eyes-only
                 Set  the  'for  your  eyes  only' flag in the message.  This
                 causes GnuPG to refuse to save the file unless the  --output
                 option  is  given, and PGP to use the "secure viewer" with a
                 Tempest-resistant font to display the message.  This  option
                 overrides  --set-filename.  --no-for-your-eyes-only disables
                 this option.

       --use-embedded-filename
                 Try to create a file with a name as embedded  in  the  data.
                 This  can  be  a  dangerous option as it allows to overwrite
                 files.

       --completes-needed n
                 Number of completely trusted users to introduce  a  new  key
                 signer (defaults to 1).

       --marginals-needed n
                 Number  of  marginally  trusted users to introduce a new key
                 signer (defaults to 3)

       --max-cert-depth n
                 Maximum depth of a certification chain (default is 5).

       --cipher-algo name
                 Use  name as cipher algorithm. Running the program with  the
                 command  --version yields a list of supported algorithms. If
                 this is not used the cipher algorithm is selected  from  the
                 preferences stored with the key.

       --digest-algo name
                 Use  name  as the message digest algorithm. Running the pro-
                 gram with the command --version yields a list  of  supported
                 algorithms.

       --cert-digest-algo name
                 Use name as the message digest algorithm used when signing a
                 key.  Running the program with the command --version  yields
                 a list of supported algorithms.  Be aware that if you choose
                 an algorithm that GnuPG supports but other OpenPGP implemen-
                 tations  do not, then some users will not be able to use the
                 key signatures you make, or quite possibly your entire  key.

       --s2k-cipher-algo name
                 Use  name  as  the  cipher  algorithm used to protect secret
                 keys.  The default cipher is CAST5.   This  cipher  is  also
                 used  for  conventional  encryption  if --cipher-algo is not
                 given.

       --s2k-digest-algo name
                 Use  name  as  the  digest  algorithm  used  to  mangle  the
                 passphrases.   The  default algorithm is SHA-1.  This digest
                 algorithm  is  also  used  for  conventional  encryption  if
                 --digest-algo is not given.

       --s2k-mode n
                 Selects  how  passphrases  are  mangled.  If  n is 0 a plain
                 passphrase (which is not recommended) will be used, a 1 adds
                 a  salt to the passphrase and a 3 (the default) iterates the
                 whole process a couple of times.  Unless --rfc1991 is  used,
                 this mode is also used for conventional encryption.

       --simple-sk-checksum
                 Secret  keys are integrity protected by using a SHA-1 check-
                 sum.  This method will be part of an enhanced OpenPGP speci-
                 fication  but  GnuPG  already  uses  it  as a countermeasure
                 against certain attacks.  Old applications don't  understand
                 this  new  format, so this option may be used to switch back
                 to the old behaviour.  Using this this option bears a  secu-
                 rity  risk.   Note  that using this option only takes effect
                 when the secret key is encrypted - the simplest way to  make
                 this  happen  is  to  change the passphrase on the key (even
                 changing it to the same value is acceptable).

       --compress-algo n
                 Use compression algorithm n.  The value 2  is  RFC1950  ZLIB
                 compression.   The value 1 is RFC-1951 ZIP compression which
                 is used by PGP.  0 disables compression.  If this option  is
                 not  used,  the default behavior is to examine the recipient
                 key preferences to see which algorithms the  recipient  sup-
                 ports.   If all else fails, ZIP is used for maximum compati-
                 bility.  Note, however, that ZLIB may give  better  compres-
                 sion  results  if that is more important, as the compression
                 window size is not limited to 8k.

       --disable-cipher-algo name
                 Never allow the use of name as cipher algorithm.  The  given
                 name  will  not  be checked so that a later loaded algorithm
                 will still get disabled.

       --disable-pubkey-algo name
                 Never allow the use of name as public  key  algorithm.   The
                 given  name will not be checked so that a later loaded algo-
                 rithm will still get disabled.

       --no-sig-cache
                 Do not cache the  verification  status  of  key  signatures.
                 Caching  gives  a  much  better performance in key listings.
                 However, if you suspect that your public keyring is not save
                 against write modifications, you can use this option to dis-
                 able the caching.  It probably does not make sense  to  dis-
                 able  it  because  all kind of damage can be done if someone
                 else has write access to your public keyring.

       --no-sig-create-check
                 GnuPG normally verifies each signature right after  creation
                 to  protect  against  bugs  and  hardware malfunctions which
                 could leak out bits from the secret key.  This extra verifi-
                 cation  needs  some  time  (about 115% for DSA keys), and so
                 this option can be used to disable it.  However, due to  the
                 fact  that  the signature creation needs manual interaction,
                 this performance penalty does not matter in most settings.

       --auto-check-trustdb

       --no-auto-check-trustdb
                 If GnuPG feels that its information about  the  Web-of-Trust
                 has to be updated, it automatically runs the --check-trustdb
                 command internally.  This may be a time  consuming  process.
                 --no-auto-check-trustdb disables this option.

       --throw-keyid
                 Do  not  put  the keyid into encrypted packets.  This option
                 hides the receiver of the message and  is  a  countermeasure
                 against  traffic  analysis.  It may slow down the decryption
                 process because all available secret keys are tried.

       --not-dash-escaped
                 This option changes the behavior of cleartext signatures  so
                 that  they  can be used for patch files. You should not send
                 such an armored file via email because all spaces  and  line
                 endings  are  hashed  too.   You can not use this option for
                 data which has 5 dashes at the beginning of  a  line,  patch
                 files  don't  have  this.  A special armor header line tells
                 GnuPG about this cleartext signature option.

       --escape-from-lines

       --no-escape-from-lines
                 Because some mailers change lines starting with "From  "  to
                 ">From  "  it  is good to handle such lines in a special way
                 when creating cleartext signatures to prevent the mail  sys-
                 tem  from  breaking  the signature.  Note that all other PGP
                 versions do it this way too.   Enabled  by  default.   --no-
                 escape-from-lines disables this option.

       --passphrase-fd n
                 Read the passphrase from file descriptor n. If you use 0 for
                 n, the passphrase will be read from stdin. This can only  be
                 used  if  only  one  passphrase is supplied.  Don't use this
                 option if you can avoid it.

       --command-fd n
                 This is a replacement for the deprecated  shared-memory  IPC
                 mode.  If this option is enabled, user input on questions is
                 not expected from the TTY but from the given  file  descrip-
                 tor.   It  should be used together with --status-fd. See the
                 file doc/DETAILS in the source distribution for  details  on
                 how to use it.

       --use-agent

       --no-use-agent
                 Try  to  use the GnuPG-Agent. Please note that this agent is
                 still under development.   With  this  option,  GnuPG  first
                 tries  to  connect  to  the  agent  before  it  asks  for  a
                 passphrase.  --no-use-agent disables this option.

       --gpg-agent-info
                 Override   the   value   of   the    environment    variable
                 GPG_AGENT_INFO.  This is only used when --use-agent has been
                 given

       Compliance options
                 These options control what GnuPG is compliant to.  Only  one
                 of  these  options  may  be active at a time.  Note that the
                 default setting of this is nearly always  the  correct  one.
                 See the INTEROPERABILITY WITH OTHER OPENPGP PROGRAMS section
                 below before using one of these options.

                 --gnupg   Use standard GnuPG behavior.  This is  essentially
                           OpenPGP  behavior  (see  --openpgp), but with some
                           additional workarounds  for  common  compatibility
                           problems  in  different  versions of PGP.  This is
                           the default option, so it is not generally needed,
                           but  it may be useful to override a different com-
                           pliance option in the gpg.conf file.

                 --openpgp Reset all packet, cipher  and  digest  options  to
                           strict OpenPGP behavior.  Use this option to reset
                           all  previous  options  like  --rfc1991,  --force-
                           v3-sigs, --s2k-*, --cipher-algo, --digest-algo and
                           --compress-algo to OpenPGP compliant values.   All
                           PGP workarounds are disabled.

                 --rfc2440 Reset  all  packet,  cipher  and digest options to
                           strict RFC-2440 behavior.  Note that this is  cur-
                           rently the same thing as --openpgp.

                 --rfc1991 Try to be more RFC-1991 (PGP 2.x) compliant.

                 --pgp2    Set  up  all options to be as PGP 2.x compliant as
                           possible, and warn if an  action  is  taken  (e.g.
                           encrypting  to  a  non-RSA key) that will create a
                           message that PGP 2.x will not be able  to  handle.
                           Note  that  'PGP  2.x' here means 'MIT PGP 2.6.2'.
                           There are other versions of PGP 2.x available, but
                           the MIT release is a good common baseline.

                           This option implies '--rfc1991 --disable-mdc --no-
                           force-v4-certs --no-sk-comment --escape-from-lines
                           --force-v3-sigs --no-ask-sig-expire --no-ask-cert-
                           expire --cipher-algo IDEA --digest-algo MD5 --com-
                           press-algo  1'.   It also disables --textmode when
                           encrypting.

                 --pgp6    Set up all options to be as  PGP  6  compliant  as
                           possible.   This restricts you to the ciphers IDEA
                           (if the  IDEA  plugin  is  installed),  3DES,  and
                           CAST5, the hashes MD5, SHA1 and RIPEMD160, and the
                           compression algorithms none and  ZIP.   This  also
                           disables --throw-keyid, and making signatures with
                           signing subkeys as PGP 6 does not understand  sig-
                           natures made by signing subkeys.

                           This option implies '--disable-mdc --no-sk-comment
                           --escape-from-lines --force-v3-sigs  --no-ask-sig-
                           expire'

                 --pgp7    Set  up  all  options  to be as PGP 7 compliant as
                           possible.  This is identical to --pgp6 except that
                           MDCs  are  not disabled, and the list of allowable
                           ciphers is expanded to add AES128, AES192, AES256,
                           and TWOFISH.

                 --pgp8    Set  up  all  options  to be as PGP 8 compliant as
                           possible.  PGP 8 is a lot closer  to  the  OpenPGP
                           standard  than  previous  versions  of PGP, so all
                           this  does  is  disable  --throw-keyid   and   set
                           --escape-from-lines.   The allowed algorithms list
                           is the same as --pgp7 with  the  addition  of  the
                           SHA-256 digest algorithm.

       --force-v3-sigs

       --no-force-v3-sigs
                 OpenPGP  states  that  an  implementation should generate v4
                 signatures but PGP versions 5 through 7  only  recognize  v4
                 signatures  on  key  material.  This option forces v3 signa-
                 tures for signatures on data.  Note that this  option  over-
                 rides --ask-sig-expire, as v3 signatures cannot have expira-
                 tion dates.  --no-force-v3-sigs disables this option.

       --force-v4-certs

       --no-force-v4-certs
                 Always use v4 key signatures even on v3 keys.   This  option
                 also changes the default hash algorithm for v3 RSA keys from
                 MD5 to SHA-1.  --no-force-v4-certs disables this option.

       --force-mdc
                 Force the use of encryption with  a  modification  detection
                 code.   This  is  always  used with the newer ciphers (those
                 with a blocksize greater than 64 bits), or  if  all  of  the
                 recipient  keys indicate MDC support in their feature flags.

       --disable-mdc
                 Disable the use of the modification  detection  code.   Note
                 that  by  using  this  option, the encrypted message becomes
                 vulnerable to a message modification attack.

       --allow-non-selfsigned-uid

       --no-allow-non-selfsigned-uid
                 Allow the import and use of keys with user IDs which are not
                 self-signed.   This is not recommended, as a non self-signed
                 user ID is trivial to forge.   --no-allow-non-selfsigned-uid
                 disables.

       --allow-freeform-uid
                 Disable all checks on the form of the user ID while generat-
                 ing a new one.  This option should only be used in very spe-
                 cial  environments  as it does not ensure the de-facto stan-
                 dard format of user IDs.

       --ignore-time-conflict
                 GnuPG normally checks that the  timestamps  associated  with
                 keys  and  signatures have plausible values.  However, some-
                 times a signature seems to be older  than  the  key  due  to
                 clock problems.  This option makes these checks just a warn-
                 ing.  See also --ignore-valid-from for timestamp  issues  on
                 subkeys.

       --ignore-valid-from
                 GnuPG  normally  does  not select and use subkeys created in
                 the future.  This option allows the use  of  such  keys  and
                 thus  exhibits  the pre-1.0.7 behaviour.  You should not use
                 this option unless you there is  some  clock  problem.   See
                 also --ignore-time-conflict for timestamp issues with signa-
                 tures.

       --ignore-crc-error
                 The ASCII armor used by OpenPGP is protected by a CRC check-
                 sum  against transmission errors.  Sometimes it happens that
                 the CRC gets mangled somewhere on the  transmission  channel
                 but  the  actual  content (which is protected by the OpenPGP
                 protocol anyway) is still okay.  This option  will  let  gpg
                 ignore CRC errors.

       --ignore-mdc-error
                 This  option changes a MDC integrity protection failure into
                 a warning.  This can be useful if  a  message  is  partially
                 corrupt, but it is necessary to get as much data as possible
                 out of the corrupt message.  However, be aware  that  a  MDC
                 protection  failure  may also mean that the message was tam-
                 pered with intentionally by an attacker.

       --lock-once
                 Lock the databases the first time a lock is requested and do
                 not release the lock until the process terminates.

       --lock-multiple
                 Release the locks every time a lock is no longer needed. Use
                 this to override a previous --lock-once from a config  file.

       --lock-never
                 Disable  locking  entirely.  This option should be used only
                 in very special environments, where it can be  assured  that
                 only  one  process  is  accessing  those  files.  A bootable
                 floppy with a stand-alone encryption  system  will  probably
                 use  this.   Improper  usage of this option may lead to data
                 and key corruption.

       --no-random-seed-file
                 GnuPG uses a file to store its  internal  random  pool  over
                 invocations.   This  makes random generation faster; however
                 sometimes write operations are not desired.  This option can
                 be  used to achieve that with the cost of slower random gen-
                 eration.

       --no-verbose
                 Reset verbose level to 0.

       --no-greeting
                 Suppress the initial copyright message.

       --no-secmem-warning
                 Suppress the warning about "using insecure memory".

       --no-permission-warning
                 Suppress the warning about unsafe file  and  home  directory
                 (--homedir)  permissions.   Note  that the permission checks
                 that GnuPG performs are not intended  to  be  authoritative,
                 but  rather they simply warn about certain common permission
                 problems.  Do not assume that the lack of  a  warning  means
                 that your system is secure.

                 Note  that the warning for unsafe --homedir permissions can-
                 not be supressed in the gpg.conf file, as this  would  allow
                 an  attacker  to place an unsafe gpg.conf file in place, and
                 use this file to supress warnings about itself.  The --home-
                 dir permissions warning may only be supressed on the command
                 line.

       --no-mdc-warning
                 Suppress the warning about missing MDC integrity protection.

       --no-armor
                 Assume the input data is not in ASCII armored format.

       --no-default-keyring
                 Do not add the default keyrings to the list of keyrings.

       --skip-verify
                 Skip  the  signature verification step.  This may be used to
                 make the decryption faster if the signature verification  is
                 not needed.

       --with-colons
                 Print  key listings delimited by colons.  Note that the out-
                 put will be encoded in UTF-8  regardless  of  any  --charset
                 setting.   This  format  is useful when GnuPG is called from
                 scripts and other programs as it is easily  machine  parsed.
                 The  details  of  this  format  are  documented  in the file
                 doc/DETAILS, which is included in the GnuPG source distribu-
                 tion.

       --with-key-data
                 Print  key listings delimited by colons (like --with-colons)
                 and print the public key data.

       --with-fingerprint
                 Same as the command --fingerprint but changes only the  for-
                 mat of the output and may be used together with another com-
                 mand.

       --fast-list-mode
                 Changes the output of the list commands to work faster; this
                 is  achieved by leaving some parts empty.  Some applications
                 don't need the user ID and the trust  information  given  in
                 the  listings.   By using this options they can get a faster
                 listing.  The exact behaviour of this option may  change  in
                 future versions.

       --fixed-list-mode
                 Do not merge primary user ID and primary key in --with-colon
                 listing mode and  print  all  timestamps  as  seconds  since
                 1970-01-01.

       --list-only
                 Changes the behaviour of some commands.  This is like --dry-
                 run but different in some cases.  The semantic of this  com-
                 mand may be extended in the future.  Currently it only skips
                 the actual decryption pass  and  therefore  enables  a  fast
                 listing of the encryption keys.

       --no-literal
                 This  is not for normal use.  Use the source to see for what
                 it might be useful.

       --set-filesize
                 This is not for normal use.  Use the source to see for  what
                 it might be useful.

       --emulate-md-encode-bug
                 GnuPG  versions prior to 1.0.2 had a bug in the way a signa-
                 ture was encoded.  This  options  enables  a  workaround  by
                 checking  faulty  signatures again with the encoding used in
                 old versions.  This may only happen for  ElGamal  signatures
                 which are not widely used.

       --show-session-key
                 Display  the  session  key used for one message. See --over-
                 ride-session-key for the counterpart of this option.

                 We think that Key-Escrow is a Bad Thing;  however  the  user
                 should have the freedom to decide whether to go to prison or
                 to reveal the content of one specific message  without  com-
                 promising  all  messages  ever encrypted for one secret key.
                 DON'T USE IT UNLESS YOU ARE REALLY FORCED TO DO SO.

       --override-session-key string
                 Don't use the public key but the session  key  string.   The
                 format  of  this  string  is  the same as the one printed by
                 --show-session-key.  This option is normally  not  used  but
                 comes handy in case someone forces you to reveal the content
                 of an encrypted message; using this option you can  do  this
                 without handing out the secret key.

       --ask-sig-expire

       --no-ask-sig-expire
                 When making a data signature, prompt for an expiration time.
                 If this option is not  specified,  the  expiration  time  is
                 "never".  --no-ask-sig-expire disables this option.

       --ask-cert-expire

       --no-ask-cert-expire
                 When  making a key signature, prompt for an expiration time.
                 If this option is not  specified,  the  expiration  time  is
                 "never".  --no-ask-cert-expire disables this option.

       --expert

       --no-expert
                 Allow  the  user to do certain nonsensical or "silly" things
                 like signing an expired or revoked key,  or  certain  poten-
                 tially  incompatible  things  like generating deprecated key
                 types.  This also disables certain  warning  messages  about
                 potentially incompatible actions.  As the name implies, this
                 option is for experts only.  If you don't  fully  understand
                 the  implications  of  what  it allows you to do, leave this
                 off.  --no-expert disables this option.

       --merge-only
                 Don't insert new keys  into  the  keyrings  while  doing  an
                 import.

       --allow-secret-key-import
                 This is an obsolete option and is not used anywhere.

       --try-all-secrets
                 Don't  look  at  the key ID as stored in the message but try
                 all secret  keys  in  turn  to  find  the  right  decryption
                 key.  This  option forces the behaviour as used by anonymous
                 recipients (created by using --throw-keyid) and  might  come
                 handy  in  case  where an encrypted message contains a bogus
                 key ID.

       --enable-special-filenames
                 This options enables a mode in which filenames of  the  form
                 -&n,  where n is a non-negative decimal number, refer to the
                 file descriptor n and not to a file with that name.

       --no-expensive-trust-checks
                 Experimental use only.

       --group name=value1 [value2 value3 ...]
                 Sets up a named group, which is similar to aliases in  email
                 programs.   Any  time  the  group name is a recipient (-r or
                 --recipient), it will be expanded to the values specified.

                 The values are key IDs or fingerprints, but any key descrip-
                 tion  is accepted.  Note that a value with spaces in it will
                 be treated as two different values.  Note also there is only
                 one  level  of  expansion  -  you  cannot make an group that
                 points to another group.  When used from the  command  line,
                 it  may be necessary to quote the argument to this option to
                 prevent the shell from treating it as multiple arguments.

       --no-groups
                 Clear the --group list.

       --preserve-permissions
                 Don't change the permissions of a  secret  keyring  back  to
                 user  read/write  only.   Use this option only if you really
                 know what you are doing.

       --personal-cipher-preferences string
                 Set the list of personal cipher preferences to string,  this
                 list  should  be  a string similar to the one printed by the
                 command "pref" in the edit menu.  This allows  the  user  to
                 factor in their own preferred algorithms when algorithms are
                 chosen via recipient key preferences.

       --personal-digest-preferences string
                 Set the list of personal digest preferences to string,  this
                 list  should  be  a string similar to the one printed by the
                 command "pref" in the edit menu.  This allows  the  user  to
                 factor in their own preferred algorithms when algorithms are
                 chosen via recipient key preferences.  The default value  is
                 "H2" indicating SHA-1.

       --personal-compress-preferences string
                 Set  the list of personal compression preferences to string,
                 this list should be a string similar to the one  printed  by
                 the  command  "pref" in the edit menu.  This allows the user
                 to factor in their own preferred algorithms when  algorithms
                 are chosen via recipient key preferences.

       --default-preference-list string
                 Set  the  list  of  default preferences to string, this list
                 should be a string similar to the one printed by the command
                 "pref"  in  the edit menu.  This affects both key generation
                 and "updpref" in the edit menu.

How to specify a user ID
       There are different ways to specify a user ID to GnuPG; here are  some
       examples:




       234567C4

       0F34E556E

       01347A56A

       0xAB123456
                 Here the key ID is given in the usual short form.

       234AABBCC34567C4

       0F323456784E56EAB

       01AB3FED1347A5612

       0x234AABBCC34567C4
                 Here the key ID is given in the long form as used by OpenPGP
                 (you can get the  long  key  ID  using  the  option  --with-
                 colons).

       1234343434343434C434343434343434

       123434343434343C3434343434343734349A3434

       0E12343434343434343434EAB3484343434343434

       0xE12343434343434343434EAB3484343434343434
                 The best way to specify a key ID is by using the fingerprint
                 of the key.  This avoids any ambiguities in case that  there
                 are  duplicated  key IDs (which are really rare for the long
                 key IDs).

       =Heinrich Heine 
                 Using an exact to match string.  The  equal  sign  indicates
                 this.

       
                 Using  the email address part which must match exactly.  The
                 left angle bracket indicates this email address mode.

       +Heinrich Heine duesseldorf
                 All words must match exactly (not case  sensitive)  but  can
                 appear in any order in the user ID.  Words are any sequences
                 of letters, digits, the underscore and all  characters  with
                 bit 7 set.

       Heine

       *Heine    By case insensitive substring matching.  This is the default
                 mode but applications may want to explicitly  indicate  this
                 by putting the asterisk in front.

       Note that you can append an exclamation mark (!) to key IDs or finger-
       prints.  This flag tells GnuPG to use exactly  the  given  primary  or
       secondary  key and not to try to figure out which secondary or primary
       key to use.


RETURN VALUE
       The program returns 0 if everything was fine, 1 if at least  a  signa-
       ture was bad, and other error codes for fatal errors.


EXAMPLES
       gpg -se -r Bob file
                 sign and encrypt for user Bob

       gpg --clearsign file
                 make a clear text signature

       gpg -sb  file
                 make a detached signature

       gpg --list-keys  user_ID
                 show keys

       gpg --fingerprint  user_ID
                 show fingerprint

       gpg --verify  pgpfile

       gpg --verify  sigfile [files]
                 Verify the signature of the file but do not output the data.
                 The second form  is  used  for  detached  signatures,  where
                 sigfile  is  the detached signature (either ASCII armored or
                 binary) and [files] are the signed  data;  if  this  is  not
                 given,  the name of the file holding the signed data is con-
                 structed by cutting off the extension (".asc" or ".sig")  of
                 sigfile or by asking the user for the filename.

ENVIRONMENT
       HOME      Used to locate the default home directory.

       GNUPGHOME If set directory used instead of "~/.gnupg".

       GPG_AGENT_INFO
                 Used  to locate the gpg-agent; only honored when --use-agent
                 is set.  The value consists of 3 colon delimited fields: The
                 first  is the path to the Unix Domain Socket, the second the
                 PID of the gpg-agent and the protocol version  which  should
                 be  set  to  1.  When starting the gpg-agent as described in
                 its documentation, this  variable  is  set  to  the  correct
                 value.   The option --gpg-agent-info can be used to override
                 it.

       http_proxy
                 Only honored when the keyserver-option  honor-http-proxy  is
                 set.

FILES
       ~/.gnupg/secring.gpg
                 The secret keyring

       ~/.gnupg/secring.gpg.lock
                 and the lock file

       ~/.gnupg/pubring.gpg
                 The public keyring

       ~/.gnupg/pubring.gpg.lock
                 and the lock file

       ~/.gnupg/trustdb.gpg
                 The trust database

       ~/.gnupg/trustdb.gpg.lock
                 and the lock file

       ~/.gnupg/random_seed
                 used to preserve the internal random pool

       ~/.gnupg/gpg.conf
                 Default configuration file

       ~/.gnupg/options
                 Old style configuration file; only used when gpg.conf is not
                 found

       /usr[/local]/share/gnupg/options.skel
                 Skeleton options file

       /usr[/local]/lib/gnupg/
                 Default location for extensions

WARNINGS
       Use a *good* password for your user account and a *good* passphrase to
       protect  your  secret key.  This passphrase is the weakest part of the
       whole system.  Programs  to  do  dictionary  attacks  on  your  secret
       keyring  are  very  easy  to  write  and  so  you  should protect your
       "~/.gnupg/" directory very well.

       Keep in mind that, if this program is used over a network (telnet), it
       is *very* easy to spy out your passphrase!

       If  you  are  going  to verify detached signatures, make sure that the
       program knows about it; either be giving both filenames on the command
       line or using - to specify stdin.

INTEROPERABILITY WITH OTHER OPENPGP PROGRAMS
       GnuPG  tries to be a very flexible implementation of the OpenPGP stan-
       dard.  In particular, GnuPG implements many of the "optional" parts of
       the  standard,  such  as the RIPEMD/160 hash, and the ZLIB compression
       algorithms.  It is important to be aware that not all OpenPGP programs
       implement  these optional algorithms and that by forcing their use via
       the --cipher-algo, --digest-algo, --cert-digest-algo,  or  --compress-
       algo  options  in  GnuPG,  it  is possible to create a perfectly valid
       OpenPGP message, but one that cannot be read by the  intended  recipi-
       ent.

       For  example,  as of this writing, no version of official PGP supports
       the BLOWFISH cipher algorithm.  If you use it, no  PGP  user  will  be
       able to decrypt your message.  The same thing applies to the ZLIB com-
       pression algorithm.  By default, GnuPG uses  the  OpenPGP  preferences
       system  that  will  always do the right thing and create messages that
       are usable by all recipients, regardless of which OpenPGP program they
       use.   Only override this safe default if you know what you are doing.

       If you absolutely must override the safe default, or  if  the  prefer-
       ences  on  a given key are invalid for some reason, you are far better
       off using the  --pgp2,  --pgp6,  --pgp7,  or  --pgp8  options.   These
       options  are  safe  as  they do not force any particular algorithms in
       violation of OpenPGP, but rather reduce the available algorithms to  a
       "PGP-safe" list.

BUGS
       On many systems this program should be installed as setuid(root). This
       is necessary to lock memory pages. Locking memory pages  prevents  the
       operating  system  from  writing  memory  pages to disk. If you get no
       warning message about insecure memory your operating  system  supports
       locking  without being root. The program drops root privileges as soon
       as locked memory is allocated.



                                                                       gpg(1)