Resisting Traitors in Linkable Democratic Group Signatures
Linkable Democratic Group Signatures (LDGS) allow every member of a group to trace the identity of any other member who issued a signature while non-members (with the help of unique pseudonyms) are only able to link the signatures issued by the same signer without being able to trace the signer's identity. LDGS avoid centralized management authorities (group managers) and grant each group member the power to trace and identify the signer. Although LDGS add nice properties to group signatures, allowing each member of the group to trace the signer's identity requires a full trust in each group member not to trace or disclose the identity of the signer without a legal reason (e.g. a dispute).