|Title||:||An Efficient Certificateless Proxy Re-Encryption Scheme without Pairing|
|Speaker||:||Arinjitha Paul (IIT Madras)|
|Details||:||Fri, Sep 15, 2017 11:00 AM, @ Turing Hall|
|Abstract||:||Proxy re-encryption (PRE) is a cryptographic primitive introduced by Blaze, Bleumer and Strauss to provide delegation of decryption rights. PRE allows re-encryption of a ciphertext intended for Alice to a ciphertext for Bob via a semi-honest proxy, who should not learn anything about the underlying message. In 2003, Al-Riyami and Patterson introduced the notion of certificateless public key cryptography which offers the advantage of identity-based cryptography without suffering from the key escrow problem. The existing certificateless PRE (CLPRE) schemes rely on costly bilinear pairing operations. In ACM ASIA-CCS SCC 2015, Srinivasan et al. proposed the first construction of a certificateless PRE scheme without resorting to pairing in the random oracle model. However, in this work, we demonstrate a flaw in the CCA-security proof of their scheme. Also, we present the first construction of a CLPRE scheme without pairing which meets CCA security under the computational Diffie-Hellman hardness assumption in the random oracle model.|
This is joint work with S.Sharmila Deva Selvi and C. Pandu Rangan, and is accepted at Eleventh International Conference on Provable Security (ProvSec 2017).