Blockchain Papers

K. Subramani

No abstract is available for this record.

Iftach Haitner, Omer Reingold

Interactive hashing, introduced by Naor, Ostrovsky, Venkatesan, and Yung (J. Cryptol. 11(2):87–108, 1998 ), plays an important role in many cryptographic protocols. In particular, interactive hashing is a major component in all known constructions of statistically hiding commitment schemes and of statistical zero-knowledge arguments based on general one-way permutations/functions. Interactive hashing with respect to a one-way function f is a two-party protocol that enables a sender who knows y = f ( x ) to transfer a random hash z = h ( y ) to a receiver such that the sender is committed to y : the sender cannot come up with x and x ′ such that f ( x )≠ f ( x ′), but h ( f ( x ))= h ( f ( x ′))= z . Specifically, if f is a permutation and h is a two-to-one hash function, then the receiver does not learn which of the two preimages { y , y ′}= h −1 ( z ) is the one the sender can invert with respect to f . This paper reexamines the notion of interactive hashing, and proves the security of a variant of the Naor et al. protocol, which yields a more versatile interactive hashing theorem. When applying our new proof to (an equivalent variant of) the Naor et al. protocol, we get an alternative proof for this protocol that seems simpler and more intuitive than the original one, and achieves better parameters (in terms of how security preserving the reduction is).

Richard Sabey

The cipher (or athbash, under which name Web3 defines it) is a Hebrew substitution cipher which replaces the first letter of the Hebrew alphabet (aleph, 1\) by the last (tav, ) the second (beth, J) by the last but one (shin, IJI), and so on, unti I we get to the last (ta , n), which i replaced by the first (aleph, 1\). Jan Anderson described it in Fledge Ledge Edge (WW 8. 1997229). Naturally, the idea can be applied to our alphabet; following the precedent set by atbash I name it the azby cipher.

Werner Kuich

No abstract is available for this record.