Cryptology ePrint Archive: Report 2018/479

On the security of Jhanwar-Barua Identity-Based Encryption Scheme

Adrian G. Schipor

Abstract: In 2008, Jhanwar and Barua presented an improvement of the Boneh-Gentry-Hamburg (BGH) scheme. In addition to reducing the time complexity of the algorithm to find a solution of the equation $ax^2+Sy^2\equiv 1 \bmod n$, their scheme reduces the number of equations to be solved by combining existing solutions. Susilo et al. extended the Jhanwar-Barua scheme, reducing more the number of equations to be solved. This paper presents a security flaw that appears in both schemes and shows that they are not IND-ID-CPA secure.

Category / Keywords: public-key cryptography / identity based encryption, ibe

Date: received 20 May 2018

Contact author: agschipor at gmail com

Available format(s): PDF | BibTeX Citation

Version: 20180523:024240 (All versions of this report)

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