Show that an encrypted message was signed, without decrypting it

Stefan Claas sac at
Sun Oct 11 02:40:28 CEST 2020

Hi Werner and all,

I was reading old GnuPG threads were people were asking if it's possible
to extract a signature from an encrypted message.

I would like to ask, I don't know if this is already possible or if it's planned,
if Alice would request from Bob that he always signs his messages and Bob, lazy
as he is, often forgets this, can Alice check if Bob's encrypted message(s) have
signed byte(s) set, without actually decrypting or revealing Bob's identity? If
the encrypted messages would not be signed then Alice can simply discard the
message(s). And is this optional in GnuPG, in case it is already implemented?


NaClbox: cc5c5f846c661343745772156a7751a5eb34d3e83d84b7d6884e507e105fd675
  The computer helps us to solve problems, we did not have without him.

More information about the Gnupg-users mailing list