An improved construction for universal re-encryption

Abstract

Golle et al recently introduced universal re-encryption, denning 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 al's techniques for universal re-encryption are reviewed, and a hybrid universal re-encryption construction with improved work and space requirements which also permits indefinite re-encryptions is presented. Some implementational issues and optimisations are discussed.