1. Bellare, M., Goldreich, O., “On Defining Proofs of Knowledge,” Advances in Cryptology — CRYPTO '92, Lecture Notes in Computer Science, no. 740, Springer-Verlag, pp. 390–420.
2. Bos, J., Chaum, D., “SmartCash: A Practical Electronic Payment System,” Centrum voor Wiskunde en Informatica, Report CS-R9035, August 1990.
3. Brands, S., “Untraceable Off-Line Cash in Wallet with Observers,” Advances in Cryptology — CRYPTO '93, Lecture Notes in Computer Science, no. 773, Springer-Verlag, pp. 302–318. An extended pre-print appeared as: “An efficient off-line electronic cash system based on the representation problem,” Centrum voor Wiskunde en Informatica, Report CS-R9323, March 1993. Available by anonymous ftp from: ftp.cwi.nl:/pub/CWIreports/AA/CS-R9323.ps.Z.
4. Brands, S., manuscript (1993). The following parts have been submitted for publication, and are available as pre-prints: (i) “Secret-Key Certificates,” (ii) “Restrictive Blinding of Secret-Key Certificates,” [(iii) is this paper], (iv) “Extensions of Off-Line Cash,” and (v) “Privacy-protecting Digital Credentials Based on Restrictive Blinding.”
5. Brands, S., “Off-line Cash Transfer by Smart Cards,” Centrum voor Wiskunde en Informatica, Report CS-R9455, September 1994. Available by anonymous ftp from: ftp.cwi.nl:/pub/CWIreports/AA/CS-R9455.ps.Z. Also in: Proceedings of the First Smart Card Research and Advanced Application Conference, France, October 1994, pp. 101–117.