Volume 3 - Issue 3 - 4
Lattice Based Identity Based Proxy Re-Encryption Scheme
- Kunwar Singh
National Institute of Technology Tiruchirappalli, India
kunwar@nitt.edu
- C Pandu Rangan
Indian Institute of Technology Madras, Chennai, Tamil Nadu, India
banerjee@nitt.edu
- A.K. Banerjee
National Institute of Technology Tiruchirappalli, India
rangan@cse.iitm.ac.in
Keywords: Lattice, Identity Based Encryption, Proxy Re-encryption, Random Oracle Model, Learn- ing With Error (LWE).
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 [20] and this strong trapdoor is shown to be very efficient [6].