Secure multiparty computationFrom CryptoDox, The Online Encyclopedia on Cryptography and Information SecurityIn cryptography, secure multiparty computation is a problem that was initially suggested by Andrew C. Yao in a 1982 paper ^{[1]}. In that publication, the millionaire problem was introduced: Alice and Bob are two millionaires who want to find out which is richer without revealing the precise amount of their wealth. Yao proposed a solution allowing Alice and Bob to satisfy their curiosity while respecting the constraints. This problem and result gave way to a generalization called multiparty computation (MPC) protocols. In a MPC, we have a given number of participants p1, p2, ..., pN, each having a private data, respectively d1, d2, ..., dN. The participants want to compute the value of a public function F on N variables at the point (d1, d2, ..., dN). A MPC protocol is dubbed secure if no participant can learn more from the description of the public function and the result of the global calculation than what he/she can learn from his/her own entry  under particular conditions depending on the model used. Like many cryptographic protocols, the security of an MPC protocol can rely on different assumptions:
An important primitive in MPC is oblivious transfer. Unconditionally or Information Theoretic Secure multiparty computations are closely related to the problem of secret sharing, and more specifically verifiable secret sharing (VSS); every secure MPC protocol that protects against active adversaries uses VSS. Secure MPC provides solutions to various reallife problems such as distributed voting, private bidding and auctions, sharing of signature or decryption functions, private information retrieval, etc. TwoParty ComputationThe subproblem of MPC that has received special attention by researchers because of its close relation to many cryptographic tasks is secure twoparty computation (2PC). This area of research is concerned with the question: 'Can two party computation be achieved more efficiently and under weaker security assumptions than general MPC?' References
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