A Framework for Licensed Digital Signatures

Digital signatures are generally used for integrity of the signed media and authentication of the signers. Beyond these the signature might provide an authorization service for a verifier to check whether the signer has license to sign the document in workflow. This verification is important in case of exchanging letters between different organizational levels and also in digital document archive. We describe the necessity of signature authorization and also describe how it can be done with two different approaches. Finally we have proposed a license structure for digital signature and a framework where signatures realize authorization of the signer.