Paper 2018/603

Actively Secure OT-Extension from q-ary Linear Codes

Ignacio Cascudo and René Bødker Christensen and Jaron Skovsted Gundersen

Abstract

We consider recent constructions of $1$-out-of-$N$ OT-extension from Kolesnikov and Kumaresan (CRYPTO 2013) and from Orrú et al. (CT-RSA 2017), based on binary error-correcting codes. We generalize their constructions such that $q$-ary codes can be used for any prime power $q$. This allows to reduce the number of base $1$-out-of-$2$ OT's that are needed to instantiate the construction for any value of $N$, at the cost of increasing the complexity of the remaining part of the protocol. We analyze these trade-offs in some concrete cases.