The Legal Classification of Identity-Based Signatures

Identity-based cryptography has attracted attention in the cryptographic research communityin recent years. Despite the importance of cryptographic schemes for applicationsin business and law, the legal implications of identity-based cryptography have not yetbeen discussed. We investigate how identity-based signatures fit into the legal framework.We focus on the European Signature Directive, but also take the UNCITRAL Model Law onElectronic Signatures into account. In contrast to previous assumptions, identity-basedsignature schemes can, in principle, be used even for qualified electronic signatures,which can replace handwritten signatures in the member states of the European Union.We derive requirements to be taken into account in the development of future identitybasedsignature schemes.