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USER-CONTROLLED LINKABILITY OF ANONYMOUS SIGNATURE SCHEMES
PCT/EP2021/061196
Anonymous signature schemes, such as ring signatures or group signatures, allow parties to sign messages such that signatures are publicly verifiable but hide the identity of the signer within a set of potential signers. Embodiment of the present invention allow a party to prove authorship of any subset of its signatures, without revealing its identity. In other words, a signer can prove that any subset of its signatures are "linked". The current invention has direct application in IoT, blockchain, and TEE scenarios, where group or ring signatures are used to balance authentication and anonymity.
The present invention relates to a method for enhancing an anonymous signature scheme with user-controlled linkability as well as to a network device configured to act as a signer in an anonymous signature scheme. It is therefore an object of the present invention to improve and further develop ring signatures schemes and group signature schemes in such a way that a party can prove that any subset of its signatures where produced by the same entity, without revealing its identity.