Cryptology ePrint Archive: Report 2015/112

Re-encryption Verifiability: How to Detect Malicious Activities of a Proxy in Proxy Re-encryption

Satsuya Ohata and Yutaka Kawai and Takahiro Matsuda and Goichiro Hanaoka and Kanta Matsuura

Abstract: In this paper, we introduce a new functionality for proxy re-encryption (PRE) that we call re-encryption verifiability. In a PRE scheme with re-encryption verifiability (which we simply call verifiable PRE, or VPRE), a receiver of a re-encrypted ciphertext can verify whether the received ciphertext is correctly transformed from an original ciphertext by a proxy, and thus can detect illegal activities of the proxy. We formalize the security model for a VPRE scheme, and show that the single-hop uni-directional PRE scheme by Hanaoka et al. (CT-RSA 2012) can be extended to a secure VPRE scheme.

Category / Keywords: public-key cryptography / Proxy Re-encryption, Re-encryption Verifiability, Soundness

Original Publication (with major differences): CT-RSA 2015

Date: received 13 Feb 2015

Contact author: satsuya at iis u-tokyo ac jp

Available format(s): PDF | BibTeX Citation

Version: 20150224:023032 (All versions of this report)

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