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 avail­
       able.  For a more verbose documentation get the  GNU  Pri­
       vacy    Handbook    (GPH),    which    is   available   at
       http://www.gnupg.org/gph/ .  You will find a list of HOWTO
       documents at http://www.gnupg.org/docs.html .


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  symmetric cipher only.  This com­
                 mand asks for a passphrase.

       --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  argu­
                 ments,  the signature packet is read from stdin.
                 If only a sigfile is given, it may be a complete

                 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  sig­
                 nature  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  com­
                 mand  which  does  not work with detached signa­
                 tures.  The command expects the files to be ver­
                 ified  either  on  the command line or reads the
                 filenames from stdin;  each name must be on sep­
                 arate  line.  The  command is intended for quick
                 checking of many files.

       --list-keys [names]

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

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

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

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

       --fingerprint [names]
                 List all keys with their fingerprints.  This  is
                 the  same  output  as  --list-keys  but with the
                 additional output of a  line  with  the  finger­
                 print.  May also be combined with --list-sigs or
                 --check-sigs.  If this command is  given  twice,
                 the  fingerprints  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 nor­
                 mally only used interactively.

                 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  fingerprint  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.

                 revsig    Revoke a signature.   GnuPG  asks  for
                           every signature which has been done by
                           one of  the  secret  keys,  whether  a
                           revocation  certificate should be gen­
                           erated.

                 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 normally not be used
                           for encryption.

                 adduid    Create an alternate user id.

                 deluid    Delete a user id.

                 addkey    Add a subkey to this key.

                 delkey    Remove a subkey.

                 revkey    Revoke a subkey.

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

                           is changed.

                 passwd    Change the passphrase  of  the  secret
                           key.

                 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.

                 pref      List preferences.

                 showpref  More verbose preferences listing.

                 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  cal­
                 culated  trust  value.  Letters are used for the
                 values:

                 -         No ownertrust assigned / not yet  cal­
                           culated.

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

                 q         Not enough  information  for  calcula­
                           tion.

                 n         Never trust this key.

                 m         Marginally trusted.

                 f         Fully trusted.

                 u         Ultimately trusted.

       --sign-key name
                 Sign  a public key with your secret key. This is

                 --edit.

       --lsign-key name
                 Sign  a public key with your secret key but mark
                 it as non-exportable.  This is a  shortcut  ver­
                 sion of the subcommand "lsign" from --edit.

       --trusted-key long key ID
                 Assume  that  the  specified  key (which must be
                 given as a  full 8 byte key ID) is as  trustwor­
                 thy  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 recipi­
                 ent's or signator's key.

       --delete-key name
                 Remove key from the public keyring

       --delete-secret-key  name
                 Remove key from the secret and public keyring

       --delete-secret-and-public-key  name
                 Same  as  --delete-key,  but  if  a  secret  key
                 exists, it will be removed first.

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

       --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  "output".   Use together with --armor to
                 mail those keys.

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

       --export-all [names]
                 Same as --export, but also  exports  keys  which
                 are not compatible with OpenPGP.

       --export-secret-keys [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
                 extension to OpenPGP and  other  implementations
                 can  not be expected to successfully import such
                 a key.

       --import [files]

       --fast-import [files]
                 Import/merge keys. This adds the given  keys  to
                 the  keyring.   The  fast version does not build
                 the trustdb; this can be done at any  time  with
                 the command --update-trustdb.

                 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  signa­
                 tures,  user-IDs  and  subkeys.   See  also  the
                 option --allow-secret-key-import.

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

       --export-ownertrust
                 List the assigned  ownertrust  values  in  ASCII
                 format for backup purposes.

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

       --print-md algo [files]
                 Print  message  digest of algorithm ALGO for all
                 given files of stdin.  If "*" is  used  for  the
                 algorithm,  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!

                 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.


OPTIONS

       Long  options  can  be  put  in  an  options file (default
       "~/.gnupg/options").  Do not write the 2 dashes, but  sim­
       ply  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 does not make sense.

       gpg recognizes these options:

       -a, --armor
                 Create ASCII armored output.

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

       -u, --local-user name
                 Use name as the user ID to sign.  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 --recip­
                 ient  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  --recipient is not used and don't ask if

                 first one from the secret keyring or the one set
                 with --default-key.

       --no-default-recipient
                 Reset --default-recipient and  --default-recipi­
                 ent-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  recipi­
                 ents  given  either  by use of --recipient or by
                 the asked user id.  No trust  checking  is  per­
                 formed 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      Set  compression  level to n. A value of 0 for n
                 disables compression.  Default  is  to  use  the
                 default  compression level of zlib (normally 6).

       -t, --textmode
                 Use  canonical  text  mode.   If  -t  (but   not
                 --textmode)  is  used together with armoring and
                 signing,  this  enables  clearsigned   messages.
                 This  kludge  is  needed  for PGP compatibility;
                 normally you would use --sign or --clearsign  to
                 selected 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   Use batch mode.  Never ask, do not allow  inter­
                 active commands.

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

                 Disable batch mode.   This  may  be  of  use  if
                 --batch is enabled from an options file.

       --yes     Assume "yes" on most questions.

       --no      Assume "no" on most questions.

       --always-trust
                 Skip  key  validation  and assume that used keys
                 are always fully trusted.  You  won't  use  this
                 unless  you have installed some external valida­
                 tion scheme.

       --keyserver name
                 Use name to lookup keys which  are  not  yet  in
                 your keyring.  This is only done while verifying
                 messages with signatures.  The  option  is  also
                 required  for the command --send-keys to specify
                 the keyserver to where the keys should be  send.
                 All  keyservers synchronize with each other - so
                 there is no need to send keys to more  than  one
                 server.   Using  the  command "host -l pgp.net |
                 grep wwwkeys" gives you a  list  of  keyservers.
                 Because  there  is  load  balancing using round-
                 robin DNS you may notice that you get  different
                 key servers.

       --no-auto-key-retrieve
                 This option disables the automatic retrieving of
                 keys from a  keyserver  while  verifying  signa­
                 tures.  This  option  allows  you to keep a key­
                 server in the options file for  the  --send-keys
                 and --recv-keys commands.

       --honor-http-proxy
                 Try  to  access the keyserver over the proxy set
                 with the variable "http_proxy".

       --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 home-directory ("~/.gnupg" if  --homedir  is
                 not  used).  The filename may be prefixed with a
                 scheme:

                 "gnupg-ring:" is the default one.

                 "gnupg-gdbm:" may be used for a GDBM ring.  Note
                 that  GDBM  is  experimental  and  likely  to be
                 removed in future versions.

                 --no-default-keyring.

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

       --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 overrides the envi­
                 ronment variable "GNUPGHOME".

       --charset name
                 Set  the name of the native character set.  This
                 is used to convert some strings to proper  UTF-8
                 encoding.  Valid values for name are:

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

                 iso-8859-2
                           The Latin 2 set.

                 koi8-r    The usual Russian set (rfc1489).

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

       --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 home­
                 dir (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.

       --load-extension name
                 Load  an extension module. If name does not con­
                 tain    a    slash    it    is    searched    in

                 information about extensions.

       --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.

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

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

       --no-comment
                 Do  not  write  comment  packets.   This  option
                 affects    only   the   generation   of   secret
                 keys.  Please note, that this has nothing to  do
                 with the comments in clear text signatures.

       --comment string
                 Use  string as comment string in clear text sig­
                 natures.   To  suppress  those  comment  strings
                 entirely, use an empty string here.

       --default-comment
                 Force  to  write  the standard comment string in
                 clear text signatures.  Use this to overwrite  a
                 --comment from a config file.

       --no-version
                 Omit  the  version  string  in clear text signa­
                 tures.

       --emit-version
                 Force to write the version string in clear  text
                 signatures.   Use  this  to overwrite a previous
                 --no-version from a config file.

       -N, --notation-data name=value
                 Put the name value pair into  the  signature  as
                 notation   data.   name  must  consist  only  of
                 alphanumeric characters, digits  or  the  under­
                 score;  the first character must not be a digit.
                 value may be any printable string;  it  will  be
                 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).

                 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.

       --set-filename string
                 Use  string  as the name of file which is stored
                 in messages.

       --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 pro­
                 gram with the command --version yields a list of
                 supported  algorithms.  If  this is not used the
                 cipher algorithm is selected  from  the  prefer­
                 ences stored with the key.

       --digest-algo name
                 Use   name  as message digest algorithm. Running
                 the program with the command --version yields  a
                 list  of supported algorithms.  Please note that
                 using  this  option  may  violate  the   OpenPGP
                 requirement,  that  a 160 bit hash is to be used
                 for DSA.

       --s2k-cipher-algo name
                 Use  name as the cipher algorithm used  to  pro­
                 tect   secret   keys.   The  default  cipher  is
                 BLOWFISH.  This cipher is also used for  conven­
                 tional 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 RIPE-
                 MD-160.  This digest algorithm is also used  for
                 conventional  encryption if --digest-algo is not
                 given.

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

       --compress-algo n
                 Use compress algorithm  n. Default is 2 which is
                 RFC1950 compression. You may use 1  to  use  the
                 old zlib version (RFC1951) which is used by PGP.
                 The default algorithm may  give  better  results
                 because the window size is not limited to 8K. If
                 this is not used the OpenPGP behavior  is  used,
                 i.e.  the compression algorithm is selected from
                 the preferences; note, that this can't  be  done
                 if you do not encrypt the data.

       --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  algo­
                 rithm.   The  given  name will not be checked so
                 that a later loaded  algorithm  will  still  get
                 disabled.

       --no-sig-cache
                 Do not cache the verification status of key sig­
                 natures.  Caching gives a  much  better  perfor­
                 mance  in key listings.  However, if you suspect
                 that your public keyring  is  not  save  against
                 write  modifications, you can use this option to
                 disable the caching.  It probably does not  make
                 sense  to  disable 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 hard­
                 ware malfunctions which could leak out bits from
                 the secret key.  This extra  verification  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.

       --throw-keyid
                 Do  not  put  the  keyid into encrypted packets.

                 and  is  a countermeasure against traffic analy­
                 sis.  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 cleart­
                 ext signature option.

       --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. All other PGP versions  do  it  this
                 way  too.  This option is not enabled by default
                 because it would violate rfc2440.

       --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 descriptor.  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
                 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.

       --rfc1991 Try to be more RFC1991 (PGP 2.x) compliant.

       --openpgp Reset  all  packet, cipher and digest options to
                 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 also disabled.

                 OpenPGP states  that  an  implementation  should
                 generate v4 signatures but PGP 5.x recognizes v4
                 signatures only on key  material.   This  option
                 forces v3 signatures for signatures on data.

       --force-mdc
                 Force the use of encryption with appended manip­
                 ulation code.  This  is  always  used  with  the
                 newer  ciphers  (those  with a blocksize greater
                 than 64 bit).  This option might not  be  imple­
                 mented yet.

       --allow-non-selfsigned-uid
                 Allow the import of keys with user IDs which are
                 not self-signed, but have at  least  one  signa­
                 ture.  This only allows the import - key valida­
                 tion will fail and you have to check the  valid­
                 ity  of  the  key  my other means.  This hack is
                 needed for some German keys generated  with  pgp
                 2.6.3in.  You  should  really  avoid  using  it,
                 because OpenPGP has better mechanics to do sepa­
                 rate signing and encryption keys.

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

       --ignore-time-conflict
                 GnuPG  normally checks that the timestamps asso­
                 ciated with keys and signatures  have  plausible
                 values.  However, sometimes a signature seems to
                 be older than the key  due  to  clock  problems.
                 This option makes these checks just a warning.

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

       --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

                 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 access­
                 ing 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 gener­
                 ation 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  but  do
                 not enter batch mode.

       --no-secmem-warning
                 Suppress  the warning about "using insecure mem­
                 ory".

       --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.

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

       --with-fingerprint
                 Same  as  the  command --fingerprint but changes
                 only the format of the output and  may  be  used


       --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 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 command 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  signature  was  encoded.   This  options
                 enables a workaround by checking  faulty  signa­
                 tures  again  with the encoding used in old ver­
                 sions.  This may only happen for ElGamal  signa­
                 tures which are not widely used.

       --show-session-key
                 Display  the  session  key used for one message.
                 See --override-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 compromising all
                 messages  ever  encrypted  for  one  secret key.
                 DON'T USE IT UNLESS YOU ARE REALLY FORCED TO  DO
                 SO.

                 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.

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

       --allow-secret-key-import
                 Allow import of secret keys.  The import command
                 normally  skips secret keys because a secret key
                 can otherwise be used to attack the trust calcu­
                 lation.

       --try-all-secrets
                 Don't  look  at the key ID as stored in the mes­
                 sage but try all secret keys in turn to find the
                 right  decryption  key.   This option forces the
                 behaviour as used by anonymous recipients  (cre­
                 ated  by  using  --throw-keyid)  and  might come
                 handy in case where an  encrypted  message  con­
                 tains 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 deci­
                 mal  number,  refer to the file descriptor n and
                 not to a file with that name.

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


How to specify a user ID

       There are different ways on how 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.


       0F323456784E56EAB

       01AB3FED1347A5612

       0x234AABBCC34567C4
                 Here the key ID is given in  the  long  form  as
                 used by OpenPGP.

       1234343434343434C434343434343434

       123434343434343C3434343434343734349A3434

       0E12343434343434343434EAB3484343434343434

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

       =Heinrich Heine <heinrichh@uni-duesseldorf.de>
                 Using an exact to match string.  The equal  sign
                 indicates this.

       <heinrichh@uni-duesseldorf.de>
                 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 sensi­
                 tive) 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.

       #34       Using  the  Local  ID.  This is a very low level
                 method and should only be used  by  applications
                 which  really need it.  The hash character indi­
                 cates this method.        An application  should
                 not assume that this is only a number.

       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
       fingerprints.   This flag which tells GnuPG to use exactly
       that primary or secondary key and don't try to figure  out



RETURN VALUE

       The  program  returns  0  if  everything was fine, 1 if at
       least a signature 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 out­
                 put the  data.  The  second  form  is  used  for
                 detached   signatures,   where  sigfile  is  the
                 detached  signature  (either  ASCII  armored  of
                 binary) and [files] are the signed data; if this
                 is not given the name of the  file  holding  the
                 signed  data  is  constructed 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".

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


FILES

       ~/.gnupg/secring.gpg
                 The secret keyring

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

                 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/options
                 May contain options

       /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 dic­
       tionary  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  nows  about  it; either be giving both
       filenames on the commandline or using - to specify  stdin.


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  mes­
       sage  about insecure memory your operating system supports
       locking without being root. The program drops root  privi­
       leges as soon as locked memory is allocated.


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