Oblivious Transfer Based on NTRUEncrypt

Oblivious transfer (OT) is the most fundamental process in cryptosystems and serves as the basic building block for implementing protocols, such as the secure multi-party computation and the fair electronic contract. However, since most implementations of the Internet of Things are time-sensitive, existing works that are based on traditional public cryptosystems are not efficient or secure under quantum machine attacks. In this paper, we argued that the fastest known 1-out-of-n oblivious transfer (OT
_n
¹
) protocol, which was proposed by Chou, cannot achieve semantic security and is time-consuming due to exponent arithmetic of large parameters. Utilizing NTRUEncrypt and OT extension, we devised a one-round postquantum secure OT
_n
¹
protocol that is also proved to be active and adaptively secure under the universal composability framework. Compared with Chou's protocol, the computational overheads of our scheme are approximately 6 and 1.7 times smaller on the sender and receiver sides, in line with the standard security level.