Selected presentations and publications

Recent Presentations

• Introduction to Cryptography, a short (5-hour) course on Cryptography and its applications. Recorder by Network Northeastern. Contact NTU for (video) copies.
• Security proofs for practical encryption schemes, invited presentation at Lucent Technologies, Bell Labs, April 17, 98. For a technical view, refer to the paper published in PKC '98 on ElGamal encryption.
• Fast A-Key distribution with OTASP, presented in the January '97 AHAG meeting, January 8th, '98, New Orleans, LA. The related paper has been accepted in the IEEE Symposium of Security and Privacy.
• Invited talk on Balancing Anonymity and Accountability, as part of a panel discussion given at the University of Wisconsin at Milwaukee, December 12th, 1997. An abstract is available. A relevant article on anonymous cash appeared in the Milwaukee Journal of 12/15/97.
• Invited talk on Anonymity in Electronic Commerce, as part of a panel discussion given at the 22nd Conferece on Local Computer Networks (LCN '97), Minneapolis, Minessota, November 4th, 1997.
• Invited talk on Micropayments and anonymous e-cash, for the IEEE local (New England) chapter, February 13, 1997. Powerpoint 4.0 slides are also available.

Selected Publications

1. Efficient Electronic Cash: New Notions and Techniques (1.15 Mb), my Ph.D. thesis. Browse the abstract, or you may choose to download the compressed postscript (500Kb). Other options available, but you have to contact me first... Note: the RBC protocol in Chapter 5 must be corrected (as in the "easy come-easy go divisible cash" below). A corrected version will be posted here shortly.
2. Decision oracles are equivalent to matching oracles, with Helena Handschuh and Moti Yung. To appear in 1999 International Workshop on Practice and Theory in Public Key Cryptography '99 (PKC '99), Kamakura, Japan, March 1-3 1999.
3. Easy come-easy go divisible cash, (updated version, GTE Tech report with corrections on RBC) with Yair Frankel and Agnes Chan. Eurocrypt '98, Lecture Notes in Computer Science, Elsinki, Finland, May 31-June 4 '98. pp. 561-575. Abstract and compressed postscript are also available.
4. Indirect Discourse Proofs: Achieving Fair Off-Line Electronic Cash, with Yair Frankel and Moti Yung. Asiacrypt '96, Lecture Notes in Computer Science 1163, pages 286-300, November 3-7, South Korea. Abstract, compressed postscript.
5. On the security of ElGamal-based encryption, with Moti Yung. In 1998 International Workshop on Practice and Theory in Public Key Cryptography (PKC '98), February 5-6, Yokohama, Japan. Abstract, compressed postscript, powerpoint slides.
6. Exact Analysis of Exact Change, with Yair Frankel and Boaz Patt-Shamir. The 5th Israel Symposium on the Theory of Computing Systems (ISTCS '97), June 17-19, Ran-Gatan Israel, pages 107-119, IEEE Computer Society Press.

Abstract, powerpoint slides, compressed postscript.
7. Efficient key distribution for slow computing devices: Achieving fast over-the-air activation for wireless systems, with Chris Carroll and Yair Frankel. In IEEE Symposium on Security and Privacy (S&P '98), May 3-6 '98, Oakland, CA. Astract, pdf, compressed postscript. Copyright, IEEE.
8. Anonymity Control in E-Cash Systems, with George Davida, Yair Frankel and Moti Yung. Financial Cryptography '97, Anguilla, British West Indies, February 24-27. Abstract, compressed postscript.
9. Misrepresentation of identities in e-cash schemes and how to prevent it, with Agnes Chan, Yair Frankel, and Phil MacKenzie. Asiacrypt '96, Lecture Notes in Computer Science 1163, pages 276-285, November 3-7, South Korea. Abstract, compressed postscript.
10. Fair Off-Line Cash made easy, Asiacrypt '98, Beijing, China, October 18-22. Lecture Notes in Computer Science.  Compressed postscript.

 

Corrections on "Fair Off-Line E-Cash":

• The proof of theorem 1, part (2) needs to be slightly modified; download the paper from this site which is corrected in this respect.
• We apologize to the authors of "Digital Payment Systems with Passive Anonymity-Revoking Trustees", J. Camenisch, U. Maurer and M. Stadler, for mentioning in the published version of our paper above that "based on initial calculations their solution is perhaps less efficient than ours"; this clearly is not the case, with their result requiring about half the computation and communication overhead of ours. However our model is stronger, allowing the bank to perform a search on the account database, instead of the withdrawal database, when owner tracing ("payment-based revokation") is to be implemented. In addition we provide security proofs for several of our protocols. The paper as it appears on this site is corrected on this respect. The "Anonymity Control in E-Cash Systems" paper improves on our result, bringing it on par in terms of efficiency with "Digital Payment Systems with Passive Anonymity-Revoking Trustees"; however our proofs still hold, thus distinguishing our system from a security standpoint.

Detailed vitae

This cite has been accessed  times since December 4, 1997.

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