Cryptology ePrint Archive: Report 2015/083
Key Recovery Attacks against NTRU-based Somewhat Homomorphic Encryption Schemes
Massimo Chenal and Qiang Tang
Abstract: A key recovery attack allows an attacker to recover the private key of an underlying encryption scheme when given a number of decryption oracle accesses. Previous research has shown that most existing Somewhat Homomorphic Encryption (SHE) schemes suffer from this attack. In this paper, we propose efficient key recovery attacks against two NTRU-based SHE schemes, which have not gained much attention in the literature. One is published by Lopez-Alt et al. at STOC conference 2012 and the other is published by Bos et al. at the IMACC conference 2013. Parallel to our work, Dahab, Galbraith and Morais have also proposed similar attacks but only for specific parameter settings at ICITS conference 2015. In comparison, our attacks apply to all parameter settings and are more efficient than theirs.
Category / Keywords: Somewhat Homomorphic Encryption, Key Recovery Attack, IND-CCA1 Security.
Date: received 3 Feb 2015, last revised 8 May 2015
Contact author: massimo chenal at uni lu
Available format(s): PDF | BibTeX Citation
Version: 20150508:122052 (All versions of this report)
Short URL: ia.cr/2015/083
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