Direct Constructions of Bidirectional  Proxy Re-Encryption with Alleviated Trust in Proxy

Jian Weng; Yunlei Zhao

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Paper 2011/208

Direct Constructions of Bidirectional Proxy Re-Encryption with Alleviated Trust in Proxy

Jian Weng and Yunlei Zhao

Abstract

In this work, we study (the direct constructions of) bidirectional proxy re-encryption (PRE) with alleviated trust in the proxy, specifically the master secret security (MSS) and the non-transitivity (NT) security, in the standard model, and achieve the following: 1. A multi-hop MSS-secure bidirectional PRE scheme with security against chosen plaintext attacks (CPA) in the standard model, where the ciphertext remains constant size regardless of how many times it has been re-encrypted. To the best of our knowledge, there exists previously no MSS-secure multi-hop bidirectional PRE scheme with constant size of ciphertexts (whether in the random oracle model or not). 2. A single-hop MSS-secure and non-transitive bidirectional PRE scheme with security against chosen ciphertext attacks (CCA) in the standard model. The CCA-secure scheme is based on the CPA-secure scheme, and particularly employs a new re-encryption key (REK) generation mechanism to which each user makes equal contributions, where a \emph{single} REK is used in both directions with the same proxy computation. Single-hop non-transitive bidirectional PRE schemes also enjoy better fine-grained delegate right control (against malicious proxy). The security analysis uses Coron's technique [Coron, Crypto 2000], which particularly allows adaptive secret key corruption. Along the way, we also refine and clarify the security models for bidirectional PRE.

Metadata

Available format(s): PDF PS
Category: Public-key cryptography
Publication info: Published elsewhere. Unknown where it was published
Keywords: public key cryptography
Contact author(s): cryptjweng @ gmail com
History: 2011-05-08: last of 2 revisions; 2011-05-06: received; See all versions
Short URL: https://ia.cr/2011/208
License: CC BY

BibTeX

@misc{cryptoeprint:2011/208,
      author = {Jian Weng and Yunlei Zhao},
      title = {Direct Constructions of Bidirectional  Proxy Re-Encryption with Alleviated Trust in Proxy},
      howpublished = {Cryptology ePrint Archive, Paper 2011/208},
      year = {2011},
      note = {\url{https://eprint.iacr.org/2011/208}},
      url = {https://eprint.iacr.org/2011/208}
}