Section: New Results
New Primitives (Anonymity)
Participants : Michel Ferreira Abdalla, Georg Fuchsbauer, Malika Izabachène, David Pointcheval, Damien Vergnaud.
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Fair E-Cash: Be Compact, Spend Faster (ISC '09)
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Transferable Anonymous Constant-Size Fair E-Cash (CANS '09)
We focused on the specific topic of anonymous electronic money: e-cash can be spent and even transfered (to an other user) in an anonymous way. However, in case of double-spending, a trusted third party is able to open the identity of the defrauder. Efficiency (computation and communication) is also considered.
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Provably Secure Code-Based Threshold Ring Signatures (Cryptography and Coding '09)
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Group Signatures with Verifier-Local Revocation and Backward Unlinkability in the Standard Model (CANS '09)
Signing in the name of a group of players is a fundamental primitive in cryptography: ring signatures allow to do so in a perfect anonymous way; group signatures provide the ability to open the identity of the actual signer in case of abuse.
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Anonymous Consecutive Delegation of Signing Rights: Unifying Group and Proxy Signatures (Formal to Practical Security)
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Proofs on Encrypted Values in Bilinear Groups and an Application to Anonymity of Signatures (Pairing '09)
These papers develop models and tools in order to delegate some rights, in such a way that the delegatee's signature is indistinguishable from the delegator's signature: anonymity is guaranteed, except for the delegator who can recover the identity of the actual delegatee who signed in his name.
