Equational Security Proofs of Oblivious Transfer Protocols

Momeng Liu, Yupu Hu

Christian Schaffner

We present simple protocols for oblivious transfer and password-based identification which are secure against general attacks in the noisy-quantum-storage model as defined in R. K\"onig, S. Wehner, and J. Wullschleger [e-print arXiv:0906.1030]. We argue that a technical tool from K\"onig et al. suffices to prove security of the known protocols. Whereas the more involved protocol for oblivious transfer from K\"onig et al. requires less noise in storage to achieve security, our ``canonical'' protocols have the advantage of being simpler to implement and the security error is easier control. Therefore, our protocols yield higher OT rates for many realistic noise parameters. Furthermore, a proof of security of a direct protocol for password-based identification against general noisy-quantum-storage attacks is given.

博昭 小黒, Hiroaki Oguro, 茂樹 萩原 +3 more

Hangchao Ding, Han Jiang, Qiuliang Xu

We construct a universal composable framework for two-message oblivious transfer protocols based on lattice-assumption. Compared with the paper proposed by Liu and Hu, we modify a framework proposed by Liu and Hu by adding three tools, which are XOR, Bit Commitment and Smooth Projective Hash Function (SPHF). We instantiate Hash Function as SPHF, which can be more secure in practical application and can achieve full-simulatable in security proof. Compared with Hash Function used as Random Oracle in security proof, this construction is more secure and efficient in security proof. In particular, we mainly consider full-simulatable in simulation, which simulator can simulate any corruption cases. So we mainly consider non-adaptively malicious adversary in Oblivious Transfer protocols.

Mehrad Jaberi, Hamid Mala

Chuan Zhao, Han Jiang, Xiaochao Wei +1 more

Oblivious transfer is a fundamental tool in modern cryptography. It plays an important role in the research of security protocols. In recent years, many oblivious transfer variants with more powerful functionalities are proposed, so as to be fit in different kinds of requirements and scenarios. In this paper, a new oblivious transfer variant, called cut-and-choose bilateral oblivious transfer, is proposed. Based on homomorphic encryption, an efficient one-round protocol of this primitive is constructed, accompanied with rigorous security proof in semi-honest model. When applied in security protocols based on cut-and-choose technique (especially in secure two-party computation), cut-and-choose bilateral oblivious transfer enables a more modular high-level description of the protocol framework, as well as reduces the round complexity of the protocols. Besides, as a basic tool in the information security area, this primitive itself is of independent research interest.