This note points out a gap between two natural formulations of
the concept of a proof of knowledge, and shows that in all
natural cases (e.g., NP-statements) this gap can be closed.
The aforementioned formulations differ by whether they refer to
(all possible) probabilistic or deterministic prover strategies.
Unlike ... more >>>

Knowledge extraction is a fundamental notion, modeling knowledge possession in a computational complexity sense. The notion provides a tool for cryptographic protocol design and analysis, enabling one to argue about the internal state of protocol players. We define and
investigate the relative power of the notion of ``concurrent knowledge-extraction'' ... more >>>

A major difficulty in quantum rewinding is the fact that measurement is destructive: extracting information from a quantum state irreversibly changes it. This is especially problematic in the context of zero-knowledge simulation, where preserving the adversary's state is essential.

In this work, we develop new techniques for ... more >>>