Non-interactive Zaps of Knowledge

Georg Fuchsbauer (1) , Michele Orrù (1)

1 CASCADE - Construction and Analysis of Systems for Confidentiality and Authenticity of Data and Entities

While non-interactive zero-knowledge (NIZK) proofs require trusted parameters, Groth, Ostrovsky and Sahai constructed non-interactive witness-indistinguishable (NIWI) proofs without any setup; they called their scheme a non-interactive zap. More recently, Bellare, Fuchsbauer and Scafuro investigated the security of NIZK in the face of parameter subversion and observe that NI zaps provide subversion-resistant soundness and WI. Arguments of knowledge prove that not only the statement is true, but also that the prover knows a witness for it, which is essential for anonymous identification. We present the first NIWI argument of knowledge without parameters, i.e., a NI zap of knowledge. Consequently, our scheme is also the first subversion-resistant knowledge-sound proof system, a notion recently proposed by Fuchsbauer.

Domaines: Cryptographie et sécurité [cs.CR]

Georg Fuchsbauer, Michele Orrù. Non-interactive Zaps of Knowledge. ACNS 2018 - 16th International Conference on Applied Cryptography and Network Security, Jul 2018, Leuven, Belgium. pp.44-62, ⟨10.1007/978-3-319-93387-0_3⟩. ⟨hal-01870005⟩