On Round-Efficient Argument Systems [chapter]

Hoeteck Wee
2005 Lecture Notes in Computer Science  
We consider the problem of constructing round-efficient public-coin argument systems, that is, interactive proof systems that are only computationally sound with a constant number of rounds. We focus on argument systems for NTime(T (n)) where either the communication complexity or the verifier's running time is subpolynomial in T (n), such as Kilian's argument system for NP [Kil92] and universal arguments [BG02, Mic00] . We begin with the observation that under standard complexity assumptions,
more » ... uch argument systems require at least 2 rounds. Next, we relate the existence of non-trivial 2-round argument systems to that of hard-on-average search problems in NP and that of efficient public-coin zero-knowledge arguments for NP. Finally, we show that the Fiat-Shamir paradigm [FS86] and Babai-Moran round reduction [BM88] fails to preserve computational soundness for some 3-round and 4-round argument systems.
doi:10.1007/11523468_12 fatcat:x3k2vjcelzct5oggyjy2kujd3y