Redactable vs. Sanitizable Signatures
نویسندگان
چکیده
Malleable signature schemes allow altering signed data in a controlled way while keeping the signature verifiable trusting the signer’s key. Several constructions exists. They can be grouped in two different categories: (1) redactable signatures (RSS) and (2) sanitizable signatures (SSS). RSSs allow for removing blocks of a signed document, while SSSs offer the possibility to change all admissible blocks to arbitrary strings. This paper shows that SSSs with a strenghted security definition can be transformed into RSSs with a weakened privacy definition. A transformation from a RSS into a SSS is not possible, even if we assume accountability for RSS. In particular, no unforgeable RSS can be transformed into a SSS. This work provides the first rigorous proof that RSSs and SSSs are two different concepts.
منابع مشابه
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