Cryptology ePrint Archive: Report 2003/255

Improved Constructions for Universal Re-encryption.

Peter Fairbrother

Abstract: Golle et al introduced universal re-encryption, defining it as re- encryption by a player who does not know the key used for the original encryption, but which still allows an intended player to recover the plaintext. Universal re-encryption is potentially useful as part of many information-hiding techniques, as it allows any player to make ciphertext unidentifiable without knowing the key used. Golle et alís techniques for universal re-encryption are reviewed, and improved constructions for both simple and hybrid universal re-encryption systems are presented, including a hybrid construction that permits indefinite re-encryptions with better efficiency and an almost-optimally small increase in file size. Some implementational issues and possible future directions are also discussed.

Category / Keywords: implementation / information hiding reencryption mixnet anonymity

Date: received 3 Dec 2003, last revised 30 Apr 2004

Contact author: peter at m-o-o-t org

Available format(s): Postscript (PS) | Compressed Postscript (PS.GZ) | PDF | BibTeX Citation

Note: Tidied up, new section on semantic security

Version: 20040430:221925 (All versions of this report)

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