Keywords: Lattice, Identity Based Encryption, Forward Security, Random Oracle Model, Learning With Error (LWE).
Abstract
In MIST 2012 conference Singh et al [21] presented lattice based forward-secure identity based
encryption schemes based on LWE assumption in the random oracle model as well as in the standard
model. In this paper we propose lattice based forward-secure identity based encryption scheme
with shorter ciphertext in the random oracle model. We have reduced size of the ciphertext C from
(m(i+2)+1)kZqk to (m+1)kZqk where kZqk is number of bits required to represent an element
of Zq.