There's nothing to decrypt. A signature is used to sign plaintext. DPR will do that with his public announcements. You CAN sign a message and then encrypt it, but in this case, I signed the plaintext "burner, can you verify this signature". So yes, you know how to verify a signature. Now type a message into GPG4USB, click the Sign button in the toolbar and post the output here. Remember, you're not encrypting the message, so you should still see the plaintext, but it will have a signature after it (a bunch of garbled text), but you need to post the whole thing, including the beginning line with the dashes.