A Proxy Re-Encryption Scheme with the Unforgeability of Re-Encryption Keys against Collusion Attacks

Ryotaro Hayashi; Tatsuyuki Matsushita

Paper 2014/849

A Proxy Re-Encryption Scheme with the Unforgeability of Re-Encryption Keys against Collusion Attacks

Ryotaro Hayashi and Tatsuyuki Matsushita

Abstract

Proxy re-encryption (PRE) schemes are cryptosystems which allow a proxy who has a re-encryption key to convert a ciphertext originally encrypted for one party into a ciphertext which can be decrypted by another party. In IWSEC 2011, Hayashi et al. proposed the new security notion for PRE called ``unforgeability of re-encryption keys against collusion attacks,'' UFReKey-CA for short. They proposed the PRE schemes and claimed that their schemes meet UFReKey-CA. However, Isshiki et al. pointed out that the schemes do not meet UFReKey-CA in IWSEC 2013. It is an open problem of constructing the scheme which meets UFReKey-CA. In this paper, we propose new PRE schemes which meet confidentiality (RCCA security) assuming that the q-wDBDHI problem is hard and meet UFReKey-CA assuming that the 2-DHI problem is hard.

Metadata

Available format(s): PDF
Category: Public-key cryptography
Publication info: Preprint. MINOR revision.
Keywords: proxy re-encryption non-transferability UFReKey-CA
Contact author(s): ryotaro hayashi @ toshiba co jp
History: 2014-10-22: received
Short URL: https://ia.cr/2014/849
License: CC BY

BibTeX

@misc{cryptoeprint:2014/849,
      author = {Ryotaro Hayashi and Tatsuyuki Matsushita},
      title = {A Proxy Re-Encryption Scheme with the Unforgeability of Re-Encryption Keys against Collusion Attacks},
      howpublished = {Cryptology {ePrint} Archive, Paper 2014/849},
      year = {2014},
      url = {https://eprint.iacr.org/2014/849}
}