Optimistic Blinded-key Signatures For Elgamal And Related Schemes

If autonomous mobile agents are to be used in electronic commerce environments, they must be able to sign contracts and payment orders without the need to contact their owners. As agents execute in untrusted environments, it is assumed that any information they carry can be read by a malicious host; thus, it is unwise to include secrets, such as private keys, in such agents. Sander and Tchudin proposed the concept of undetachable signatures to solve this problem, but gave no practical manifestation for it. Ferreira and Dahab's blinded-key signatures were proposed as a practical implementation of Sander and Tchudin's idea, but require the intervention of an online TTP (trusted third party). Later, they proposed an optimistic version of their blinded-key signatures based on the RSA signature scheme. Here we propose a new version of Optimistic blinded-key signatures which is based on ElGamal signatures and its variants: DSA and Schnorr. © Springer-Verlag 2004.3284254263Ferreira, L.C., Dahab, R., Blinded-key signatures: Securing private keys in mobile agents (2002) Proceedings of SAC'2002 - ACM Symposium on Applied Computing, , Madrid, SpainSander, T., Tschudin, C.F., Protecting mobile agents against malicious hosts (1998) Lecture Notes in Computer Science, 1419. , Vigna, G., ed.: Mobile Agent Security Springer-VerlagFerreira, L.C., Dahab, R., (2004) Optimistic Blinded-key Signatures, , Submited for publicationElgamal, T., A public key cryptosystem and a signature scheme based on discrete logarithms (1984) Proceedings of Crypto '84, , LNCS 196, California, USA, Springer-VerlagMenezes, A.J., Oorschot, P.C., Vanstone, S.A., (1997) Handbook of Applied Cryptography, , http://www.cacr.uwaterloo.ca/hac, CRC Press, Available onlineStinson, D., (2002) Cryptography: Theory and Practice,Second Edition, , CRC/C&HFerreira, L.C., Dahab, R., Blinded-key signatures (2001) Technical Report IC-01-015, , Instituto de Computação - Unicamp, Campinas, SP, BrazilFerreira, L.C., Uto, N., Dahab, R., Combining techniques for protecting mobile agents (2003) Actas del Segundo Congreso Iberoamericano de Seguridad Informatica CIBSI '03, , Ciudad de Mexico, Mexico, Servicio de Publicaciones del Instituto Politécnico NacionalHohl, F., Time limited blackbox security: Protecting mobile agents from malicious hosts (1998) Lecture Notes in Computer Science, 1419. , Vigna, G., ed. Mobile Agent Security. Springer-VerlagChaum, D., Blind signatures for untraceable payments (1982) Advances in Cryptology: Proceedings of Crypto'82, , Chaum, D., Rivest, R.L., Sherman, A.T., eds. Springer-VerlagWu, T., Malkin, M., Boneh, D., Building intrusion tolerant applications (1999) Proceedings of the 8th USENIX Security Symposium, pp. 79-91Boneh, D., Franklin, M., Efficient generation of shared USA keys (1997) Advances in Cryptology - Proceedings of Crypto'97, pp. 425-439. , Kaliski, B., ed. Springer-VerlagChess, D.M., Security issues in mobile code systems (1998) Lecture Notes in Computer Science, 1419, pp. 1-14. , Vigna, G., ed.: Mobile Agents and Security. Springer-VerlagCachin, C., Camenisch, J., Kilian, J., Mũller, J., One-round secure computation and secure autonomous mobile agents (2000) Proceedings of ICALP'2000Kotzanikolaou, P., Bunnester, M., Chrissikopoulos, V., Secure transactions with mobile agents in hostile environments (2000) Australasian Conference on Information Security and Privacy, pp. 289-29