Abstract (EN):
In a witness hiding protocol the prover tries to convince the verifier that he knows a witness to an instance of an NP problem without revealing the witness. We propose a new look at witness hiding based on the information conveyed in each particular instance of the protocol. We introduce the concept of individual witness hiding (IWH) and prove that zero-knowledge protocols for classical problems like HAM are not IWH. On the other hand, we show that all FewP problems have an IWH protocol. Finally, by introducing a Kolmogorov string commitment protocol we can show that all FewP problems have an IWH protocol that is zero-knowledge relative to an oracle.
Language:
English
Type (Professor's evaluation):
Scientific
No. of pages:
13