gnupg: GPG Key related Options
4.2.2 Key related options
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'--recipient NAME'
'-r'
Encrypt for user id NAME. If this option or '--hidden-recipient'
is not specified, GnuPG asks for the user-id unless
'--default-recipient' is given.
'--hidden-recipient NAME'
'-R'
Encrypt for user ID NAME, but hide the key ID of this user's key.
This option helps to hide the receiver of the message and is a
limited countermeasure against traffic analysis. If this option or
'--recipient' is not specified, GnuPG asks for the user ID unless
'--default-recipient' is given.
'--recipient-file FILE'
'-f'
This option is similar to '--recipient' except that it encrypts to
a key stored in the given file. FILE must be the name of a file
containing exactly one key. 'gpg' assumes that the key in this
file is fully valid.
'--hidden-recipient-file FILE'
'-F'
This option is similar to '--hidden-recipient' except that it
encrypts to a key stored in the given file. FILE must be the name
of a file containing exactly one key. 'gpg' assumes that the key
in this file is fully valid.
'--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.
'--hidden-encrypt-to NAME'
Same as '--hidden-recipient' but this one is intended for use in
the options file and may be used with your own user-id as a hidden
"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' and '--hidden-encrypt-to'
keys.
'--group {NAME=VALUE}'
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.
Multiple groups with the same name are automatically merged into a
single group.
The values are 'key IDs' or fingerprints, but any key description
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.
'--ungroup NAME'
Remove a given entry from the '--group' list.
'--no-groups'
Remove all entries from the '--group' list.
'--local-user NAME'
'-u'
Use NAME as the key to sign with. Note that this option overrides
'--default-key'.
'--sender MBOX'
This option has two purposes. MBOX must either be a complete user
id with a proper mail address or just a mail address. When
creating a signature this option tells gpg the user id of a key
used to make a signature if the key was not directly specified by a
user id. When verifying a signature the MBOX is used to restrict
the information printed by the TOFU code to matching user ids.
'--try-secret-key NAME'
For hidden recipients GPG needs to know the keys to use for trial
decryption. The key set with '--default-key' is always tried
first, but this is often not sufficient. This option allows
setting more keys to be used for trial decryption. Although any
valid user-id specification may be used for NAME it makes sense to
use at least the long keyid to avoid ambiguities. Note that
gpg-agent might pop up a pinentry for a lot keys to do the trial
decryption. If you want to stop all further trial decryption you
may use close-window button instead of the cancel button.
'--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-keyids' or '--hidden-recipient') and might come
handy in case where an encrypted message contains a bogus key ID.
'--skip-hidden-recipients'
'--no-skip-hidden-recipients'
During decryption skip all anonymous recipients. This option helps
in the case that people use the hidden recipients feature to hide
their own encrypt-to key from others. If one has many secret keys
this may lead to a major annoyance because all keys are tried in
turn to decrypt something which was not really intended for it.
The drawback of this option is that it is currently not possible to
decrypt a message which includes real anonymous recipients.