% gpg-connect-agent reloadagent /bye
gpg -c --no-symkey-cache your-file.txt-symmetric
-c
Encrypt with a symmetric cipher using a passphrase. [..] gpg
caches the passphrase used for symmetric encryption so that a decrypt
operation may not require that the user needs to enter the passphrase.
The option --no-symkey-cache can be used to disable this feature.
To make this setting persistent, add the option (without --) in ~/.gnupg/gpg.conf:
no-symkey-cache
