I've encrypted a file using symmetric encryption like this:
gpg --symmetric myfile
which results in a file
Alright. Now let's decrypt the file again:
gpg -o myfile --decrypt myfile.gpg
I'm being asked for the passphrase I've put on, and then I see
gpg: CAST5 encrypted data gpg: encrypted with 1 passphrase gpg: WARNING: message was not integrity protected
I'm not sure about the first and last line there.
- What is the CAST5 cipher and is it secure? I know 3DES and AES and I know those are secure.
- Why isn't it protected for integrity?
- And moreover, how do I fix this?