Product Description
High Quality Content by WIKIPEDIA articles! There is a well-known story presenting some of the ideas of zero-knowledge proofs, first published by Jean-Jacques Quisquater and others in their paper "How to Explain Zero-Knowledge Protocols to Your Children". It is common practice to label the two parties in a zero-knowledge proof as Peggy (the prover of the statement) and Victor (the verifier of the statement).In this story, Peggy has uncovered the secret word used to open a magic door in a cave. The cave is shaped like a circle, with the entrance on one side and the magic door blocking the opposite side. Victor says he'll pay her for the secret, but not until he's sure that she really knows it. Peggy says she'll tell him the secret, but not until she receives the money. They devise a scheme by which Peggy can prove that she knows the word without telling it to Victor. ... Read more

Product Description
Turing machine. Turing machine gallery, Turing machine equivalents, Register machine, Post?Turing machine, Universal Turing machine, Computational complexity theory, Algorithm, Church?Turing thesis, Alan Turing, Turing completeness, Langton's ant. ... Read more

Product Description
High Quality Content by WIKIPEDIA articles! A computational system that can compute every Turing-computable function is called Turing-complete (or Turing-powerful). Alternatively, such a system is one that can simulate a universal Turing machine.A Turing-complete system is called Turing-equivalent if every function it can compute is also Turing-computable; i.e., it computes precisely the same class of functions as do Turing machines. Alternatively, a Turing-equivalent system is one that can simulate, and be simulated by, a universal Turing machine. (All known Turing-complete systems are Turing-equivalent, which adds support to the Church-Turing thesis.) ... Read more

Product Description
High Quality Content by WIKIPEDIA articles! The universal composability (UC) framework is a means for defining the security of cryptographic protocols. The name stems from the fact that instances of protocols that are UC secure remain secure even if arbitrarily composed with other instances of the same or other protocols. An ideal functionality is a protocol in which a trusted party that can communicate over perfectly secure channels with all protocol participants computes the desired protocol outcome. We say that a cryptographic protocol that cannot make use of such a trusted party fulfils an ideal functionality, if the protocol can emulate the behaviour of the trusted party for honest users, and if the view that an adversary learns by attacking the protocol is indistinguishable from what can be computed by a simulator that only interacts with the ideal functionality. ... Read more