Lattice Based Identity Based Proxy Re-Encryption Scheme

Kunwar Singh^1*, C Pandu Rangan², and A.K. Banerjee¹

¹National Institute of Technology Tiruchirappalli, India
{kunwar, banerjee}@nitt.edu

²Indian Institute of Technology Madras
Chennai, Tamil Nadu, India
rangan@cse.iitm.ac.in

Abstract
At Eurocrypt 1998, Blaze, Bleumer and Strauss (BBS) presented a new primitive called proxy re-encryption. This new primitive allows semi trusted proxy to convert a ciphertext for Alice into a ciphertext for Bob without underlying message. Till now all the identity based proxy re-encryption schemes are based on the number theoretic assumptions like prime factorization, discrete logarithm problem etc. In this paper we propose a lattice based identity based proxy re-encryption scheme in the random oracle model for the single bit as well as for the multi-bit. Both of our schemes are anonymous, bidirectional and multi use. In these schemes, we have used Micciancio and Peikert's strong trapdoor and this strong trapdoor is shown to be very efficient.

Keywords: Lattice, Identity Based Encryption, Proxy Re-encryption, Random Oracle Model,
                 Learning With Error (LWE)

+: Corresponding author: Kunwar Singh 
Deptartment Computer Science and Engineering Department, National Institute of Technology,
Trichy, Tiruchirappalli-15, Tamilnadu, India, Tel: +91-43125013212,
Web:  http://www.nitt.edu/home/academics/departments/cse/faculty/kunwar/

Journal of Internet Services and Information Security (JISIS), 3(3/4): 38-51, November  2013 [pdf]