Lattice Based Instantiations News Today : Breaking News, Live Updates & Top Stories | Vimarsana

Policy-based signatures (PBS) were proposed by Bellare and Fuchsbauer (PKC 2014) to allow an authorized member of an organization to sign a message on behalf of the organization. The user's authorization is determined by a policy managed by the organization's trusted authority, while the signature preserves the privacy of the organization's policy. Signing keys in PBS do not include user identity information and thus can be passed to others, violating the intention of employing PBS to restrict users’ signing capability. In this work, we introduce the notion of traceability for PBS by including user identity in the signing key such that the trusted authority will be able to open a suspicious signature and recover the signer's identity should the needs arise. We provide rigorous definitions and stringent security notions of traceable PBS (TPBS), capturing the properties of PBS suggested by Bellare-Fuchsbauer and resembling the “full traceability” requirement for ....

Bellare Micciancio Warinschi Eurocrypt , Lattice Based Instantiations , Modular Constructions , Olicy Based Signatures , Zero Knowledge Proofs ,