# Are there signatures that don't have subliminal channels?

Are there signatures that don't have subliminal channels and also don't require commitments or zero-knowledge proofs?

DSA or Schnorr signatures need a nonce which can leak valuable information. There are derandomization schemes, but the verifier can't check that the signer used them without extra steps.

Is there a signature that avoids these problems?

• That's a ... fairly general definition of "a de randomization scheme". $\:$ The verifier can "be sure it was used" by putting the signature "through the modular exponentiation which is at the core of RSA", and checking whether or not the output is equal to what the first three steps produce. $\;\;\;\;$ – user991 Dec 20 '14 at 10:16