gpg symmetric encryption not working as expected

Question

How am I supposed to use gpg to symmetrically encrypt a file? When I run gpg --symmetric filename, then it prompts me for passwords as expected, and generates a filename.gpg file. However, when I run gpg -d filename.gpg, it returns

gpg: CAST5 encrypted data
gpg: encrypted with 1 passphrase
SECRET DATA HERE
gpg: WARNING: message was not integrity protected

without asking for the password

Answer 1

Recent versions of GnuPG come with a helper program gpg-agent, which handles the key and password operations and acts as a password cache. It could be that gpg-agent has cached the password you just entered.

To flush the cache, use either:

• echo reloadagent | gpg-connect-agent

• send SIGHUP: pkill -HUP -U $USER gpg-agent