Lattice Based Forward-Secure Identity Based Encryption Scheme
with Shorter Ciphertext

Kunwar Singh^1*, C. Pandurangan², and A.K.Banerjee³

¹Computer Science and Engineering Department

NIT Trichy, Tiruchirappalli, India

kunwar@nitt.edu

²Computer Science and Engineering Department
Indian Institute of Technology Madras,
Chennai, Tamil Nadu, India
prangan@cse.iitm.ac.in

³Mathematics Department

NIT Trichy, Tiruchirappalli, India

banerjee@nitt.edu

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) ´║Zq║ to (m+1) ´║Zq║ where ║Zq║ is number of bits required to represent an element of Zq.

Keywords: Lattice, Identity Based Encryption, Forward Security, Random Oracle Model, Learning With Error (LWE)

*Corresponding author: Kunwar Singh
CSE Department, NIT Trichy, Tiruchirappalli-15, Tamilnadu, India, Tel: +91-043125013212

Journal of Internet Services and Information Security (JISIS), 3(1/2): 5-19, February 2013 [pdf]