[comp.theory] Is a public key system a Zero Knowledge Proof?

jkm@mbunix.mitre.org (Millen) (06/28/90)

In article <gla.646055056@peun33> gla@nixpbe.UUCP (R. Glaschick) writes:
>In <111361@linus.mitre.org> jkm@mbunix.mitre.org (Millen) writes:
>
>>Is any public-key system a zero-knowledge proof?  ... 
>
>... [In a ZK proof] The verifyer can simulate the
>protocol without the knowledge of the Prover's secret. This is not
>true in the above scheme.

But couldn't the verifier exhaustively try all possible ciphertexts until
one decrypted properly with the public key?

-Jon Millen