The 18 June 1996 report, "How to Make a Mint: The Cryptography of Anonymous Electronic Cash", was written by Laurie Law, Susan Sabett, and Jerry Solinas of the Office of Information Security Research and Technology, Cryptology Division, NSA. It is 30 pages, as follows: INTRODUCTION Section 1. What is Electronic Cash? 1.1 Electronic Payment 1.2 Security of Electronic Payments 1.3 Electronic Cash 1.4 Multiple Spending Section 2. A Cryptographic Description 2.1 Public-Key Cryptographic Tools (One-Way Functions, Key Pairs, Signature and Identification, Secure Hashing) 2.2 A Simplified Electronic Cash Protocol 2.3 Untraceable Electronic Payments 2.4 A Basic Electronic Cash Protocol Section 3. Proposed Off-Line Implementations 3.1 Including Identifying Information (Cut and Choose, Zero-Knowledge Proofs) 3.2 Authentication and Signature Techniques (RSA Signatures, Blind RSA Signatures, The Schnorr Algorithms, Schnorr identification, Schnorr Signature, Blind Schnorr Signature, Chaum-Pederson Signature, Implementations of the Schnorr Protocols) 3.3 Summary of Proposed Implementations (Chaum-Fiat-Naor, Brands, Ferguson) Section 4. Optional Features of Off-Line Cash 4.1 Transferability 4.2 Divisibility Section 5. Security Issues 5.1 Multiple Spending Prevention 5.2 Wallet Observers 5.3 Security Failures (Types of failures, Consequences of a failure) 5.4 Restoring Traceability CONCLUSION REFERENCES - Richard Field On Oct 24, 1996 09:52:25, 'declan@well.com (Declan McCullagh)' wrote:
Just got off the phone with the NSA.
"There are so many places in the NSA that deal with cryptology we haven't been able to find the document yet. We'll call you back once we locate it and let you know if it can be released or not. We've been getting phone calls about the document. Did you read about it on the Internet?"
-Declan
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21st Century Banking Alert No. 96-10-17 October 17, 1996
National Security Agency Report Raises Systemic Security Issues Related to Anonymous Electronic Money
A recent report prepared by the Cryptology Division of the National Security Agency's Office of Information Security Research and Technology discusses the potential for security failures in certain electronic cash systems and their likely consequences. While demonstrating concern over the attributes of non-traceable electronic money, the report points out methods that may be used to minimize security breaches and losses, including limiting the number of coins that can be affected by a single compromise,
requiring traceability for large transactions or large numbers of transactions in a given period, and the creation of a mechanism to restore traceability under certain circumstances. The report contains an excellent summary of basic electronic money cryptographic tools, electronic cash protocols, authentication and signature techniques and related security issues.