On the Security of Group-based Proxy Re-encryption Scheme

Purushothama B R; B B Amberker

Paper 2013/456

On the Security of Group-based Proxy Re-encryption Scheme

Purushothama B R and B B Amberker

Abstract

Proxy re-encryption (PRE) allows a semi-trusted proxy to convert a ciphertext intended for Alice into a ciphertext for Bob without learning anything about the underlying plaintext. Chunbo Ma et al. have proposed a group based proxy re-encryption scheme to convert a ciphertext from one group to another. Any group member can independently decrypt the ciphertexts encrypted to its group. In their paper, the authors gave a security proof to say that the scheme is secure against adaptive chosen ciphertext attack. However, we highlight the flaws in their scheme and show that their scheme is not secure against adaptive chosen ciphertext attack. In this direction, we construct an adversary who issues only one decryption oracle query and break the security of their scheme with non-negligible advantage.

Note: Format and adding of author's current affiliation.

Metadata

Available format(s): PDF
Publication info: Preprint. Not published anywhere
Keywords: Public-key Cryptography Proxy Re-encryption Cryptanalysis
Contact author(s): puru @ nitgoa ac in
History: 2013-07-27: received
Short URL: https://ia.cr/2013/456
License: CC BY

BibTeX

@misc{cryptoeprint:2013/456,
      author = {Purushothama B R and B B Amberker},
      title = {On the Security of Group-based Proxy Re-encryption Scheme},
      howpublished = {Cryptology {ePrint} Archive, Paper 2013/456},
      year = {2013},
      url = {https://eprint.iacr.org/2013/456}
}