Paper 2019/212

A New Variant of the Winternitz One Time Signature Scheme Based on Graded Encoding Schemes

Hossein Oraei and Massoud Hadian Dehkordi

Abstract

The Winternitz one-time signature (WOTS) scheme, which can be described using a certain number of so-called ``function chains", plays an important role in the design of both stateless and stateful many-time signature schemes. This work introduces WOTS^GES, a new WOTS type signature scheme in which the need for computing all of the intermediate values of the chains is eliminated. This significantly reduces the number of required operations needed to calculate the algorithms of WOTS^GES. To achieve this results, we have used the concept of ``leveled" multilinear maps which is also referred to as graded encoding schemes. In the context of provable security, we reduce the hardness of graded discrete-logarithm (GDL) problem to the EU-CMA security of WOTS^GES in the standard model.