Rekeyed Digital Signature Schemes: Damage containment in the face of key exposure

Niveau: Supérieur, Bac+5
Rekeyed Digital Signature Schemes: Damage-containment in the face of key exposure Michel Abdalla? Mihir Bellare† July 2001 Abstract Motivated by the problem of delegating signing keys to vulnerable mobile devices, we de- fine rekeyed digital signature schemes. We provide an adversary model and a strong notion of security for such schemes, and show that the classic self-certification paradigm, properly imple- mented, provably meets this notion of security. We then suggest altnerative solutions, based on identification schemes, and having certain performance benefits compared to self-certification. Keywords: Digital signatures, key exposure, delegation, forward security, identification schemes, proofs of security. ?Dept. of Computer Science & Engineering, University of California at San Diego, 9500 Gilman Drive, La Jolla, California 92093, USA. E-Mail: . URL: Supported by CAPES under Grant BEX3019/95-2. †Dept. of Computer Science & Engineering, University of California at San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA. E-mail: . URL: Supported in part by a 1996 Packard Foundation Fellowship in Science and Engineering. 1

• session key


• input pk


• digital signature


• secret key


• primary public


• rekeyed encryption


• ong-schnorr scheme


• public key


• associated secret