Research And Application On Oblivious Transfer Protocol

Oblivious transfer(OT)protocol,an essential and fundamental primitive cryptographic primitive in secure multi-party computation(MPC),is a secure communication protocol that can guarantee the privacy of the parties.It is the construction foundation of MPC applications,such as private set intersection,zero-knowledge proof,bit commitment,etc.The thesis is the research on the OT protocol,and the main contents are as follows:First,we proposed an efficient oblivious transfer protocol on the elliptic curve.The protocol used the bilinear pair to ensure the correctness of the protocol.The privacy of the receiver was secure even with an adversary with infinite computational power,and the sender was secure because of the ECDLP problem.The correctness,simulation,analysis of efficiency and proof of security showed that the EB-OT protocol was efficient with low communication.Second,we proposed the OT protocols that can obtain full simulation security in the random oracle model and the standard malicious model,respectively.Protocols used the random oracle and the zero-knowledge proof to resist the malicious behaviors.The correctness,simulation,analyses of efficiency and the proofs of security in the RO model and the standard malicious model showed that the protocols could achieve full simulation security and had the advantages of efficiency and low communication.Third,we proposed a universally composable 1-out-of-2 oblivious transfer protocol with low communication and extended it with a minor tweak.This protocol obtained full simulation security based on the Mod-LWR assumption.It could achieve universally composable security(UC-secure)in the ROM by combining random OT based on the key exchange protocol with the authentication encryption algorithm.Besides,it could resist static adversary attacks by simulating all corruption cases.Based on the correctness of the protocol,simulation,analysis of the efficiency and proof of security,this protocol that could resist quantum attacks was practicable and had better efficiency and lower communication.Finally,we proposed an OT-based simultaneous signing contract protocol.A batch OT protocol is used to enhance the efficiency,which guaranteed the synchronization of the contract protocol.Based on the correctness of the protocol,analysis of efficiency and proof of security,the OSSC protocol with a short signature and low communication was efficient.