I saw that people on the dark web would sign their posts with a PGP key to prove that their account has not been compromised. I think I understand the concept of how private and public keys work but I must be missing something because I don’t see how it proves anything.
I created a key and ran gpg --export --armor fizz@… and I ran that twice and both blocks were identical. If I posted my public key block couldn’t someone copy and paste that under their message and claim to be me?
EDIT: changed encryption / decryption to signing / veryfing. Thanks for the corrections
Not an expert, those who know more please correct me.
From what I understand, what they post is not a PGP key, but the same content published in clear text signed with their private key. That way anyone can verify it with the author’s public key to check it has been generated with the private one (that only one person should have).
You’ve got it backward. You encrypt with the public key, and decrypt with the private key. Otherwise, you’re spot on.
For signing, it’s backwards - you encrypt with the private key, and then everyone else can decrypt with the public key. If that doesn’t work, they know that the message wasn’t signed by the private key paired with the public key they have, and therefore is invalid and is not to be trusted.
Signing proves authenticity (only the private key holder can sign), encryption provides privacy (only the private key holder can read)