message clearsigné

un message clearsigné reste lisible par tous, mais porte en dessous une signature pgp qui prouve qui l'a écrit et que rien n'a été modifié.

a clearsigned message is the pgp middle ground between plaintext and full encryption. the text itself remains perfectly readable - no decryption needed - but a signature block rides underneath, bound to the exact bytes of the message.

the format opens with -----begin pgp signed message-----, shows the text, then appends the signature block. lines starting with a dash get "dash-escaped" so injected fake headers cannot spoof the structure. any alteration to the text - even a changed comma or a trailing space - invalidates the signature.

this is the standard format for market announcements, vendor bulletins and dnm forum posts: everyone can read the news, but the signature settles who actually said it. when a market claims "we never said that" about a screenshot, a clearsigned original ends the argument.

verification is the same workflow as any signature check: paste message plus the author's public key into our verify tool and read the valid/invalid verdict. remember the epistemology though - a valid signature proves the key holder wrote it, and the fingerprint comparison proves the key is really theirs.