Notes to Chapter 4
notes to chapter 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

All the Web addresses included were checked when we went online, but some, inevitably, may have moved or changed.

  1. According to "Payne-O-the-Web's Cryptography Timeline" ( ), which cites David Kahn's book The Codebreakers (Macmillan, 1972). <back to text>
  1. Herbert Zim, Codes and Secret Writing (William Morrow, 1948). <back to text>
  1. Quotes from personal interviews unless otherwise indicated. <back to text>
  1. W. Diffie and M. E. Hellman, "New Directions in Cryptography," IEEE Transactions on Information Theory IT-22, no. 6 (November 1976): 644-54; R. L. Rivest, A. Shamir and L. M. Adleman, "A Method for Obtaining Digital Signatures and Public-Key Cryptosystems," Communications of the ACM 21, no. 2 (February 1978): 120-26. <back to text>
  1. Unfortunately, computers don't speak English, so to tell them what to do you need a programming language that's designed for the purpose and a program called a compiler that takes the code you write and turns it into the ones and zeros that a machine can read. C is one of the most commonly used programming languages for commercial software for personal computers, though there are others such as BASIC, which is more like English and therefore somewhat easier to learn. <back to text>
  1. The legislation was introduced by Senators Joseph Biden (D-DE) and Dennis DeConcini (D-AZ) and Representative Tom Lantos (D-CA); after being removed from S. 266, the clause resurfaced in an omnibus anti-crime bill, from which it was also removed. <back to text>
  1. Email users do have some specific rights under the Electronic Communications Privacy Act; however, how private email and other communications are varies from system to system. Always read a system's terms of service before assuming your communications are private. <back to text>
  1. The WELL's eff conference, topic 206.
    <back to text>
  1. CIX's crypto/general #294. <back to text>
  1. An operating system is a vital layer between a software program and a computer that incorporates standard functions for controlling the machine. UNIX, because it is free and the source code was available for individual users to modify and improve, is extremely popular in the academic world. Since universities were among the earliest users of the Internet, UNIX is common on the Net, even though personal computers sold for home use typically come with the Microsoft proprietary operating systems DOS and/or Windows. <back to text>
  1. For a discussion of the issues surrounding software patenting, see Simon L. Garfinkel, Richard M. Stallman, and Mitchell Kapor, "Why Patents Are Bad for Software," and, arguing the case for patents, Paul Heckel, "Debunking the Software Patent Myths," both reprinted in High Noon on the Electronic Frontier, edited by Peter Ludlow (MIT Press, 1996), 35-107.
    <back to text>
  1. Notably James Love, director of the Washington-based Consumer Project on Technology, and University of California at Berkeley professor Pamela Samuelson.
    <back to text>
  1. RFC stands for "request for comments." These collaboratively written documents define the standards on which the Internet operates. The latest version of the RFC relevant to securing email is RFC1421. All RFCs can be retrieved via FTP from, as /rfc/rfcxxxx.txt replacing xxxx with the RFC's number.
    <back to text>
  1. From the PGP Web site, More information on where to find PGP is available in the "Where to find PGP" FAQ, which is posted regularly to alt.answers, alt.2600,, and It's also archived on the Web at Within the United States, the primary site is PGP's own site,
    <back to text>
  1. A personal prediction: when PGP Inc. gets really big and successful, a conspiracy theory will hatch on the Net to the effect that the government knows there is a fundamental weakness in PGP, and that it investigated Zimmerman precisely in order to make PGP look good so people would use it widely. <back to text>
  1. 16. A switch is a single-letter command you type in when you start the program that toggles on or off some particular feature. <back to text>
  1. In a UNIX-based system, a signature is known as .sig because that's the name of the file. Most Usenet newsreader software lets you specify a signature that will be appended to all the messages you post. People post all kinds of things in their .sigs: their addresses and phone numbers, ASCII art, and favorite quotations. One .sig that was common in the early 1990s that expressed support for the free availability of encryption ran, "If encryption is outlawed, then only outlaws will have encryption." My favorite, though, has always been, "If you're not part of the solution, you're part of the precipitate."
    <back to text>
  1. See "Why Cryptography is Harder than it Looks," by Bruce Schneier ( ), author of Applied Cryptography, and also the "Snake-Oil Warning Signs: Encryption Software to Avoid" FAQ, maintained by Matt Curtin at <back to text>
  1. Unfortunately, this posting seems to have vanished and is not archived at Deja News. However, the letter from the Special Master, Beth Hamilton, was posted pseudonymously to alt.religion.scientology (message ID 4tb7hr$ on July 26, 1996, two days after it was written, and said in part, "The computer technicians were not able to decrypt any of the PGP files except the one that contained viruses." A copy of the Special Master's letter to the court explaining her failure to decrypt Ward's PGP-encrypted hard drive is archived on Ron Newman's Web site, at, and mirrored at <back to text>


Copyright © 1997-99 NYU Press. All rights reserved.
Reproduction in whole or in part in any form or medium without written permission of New York University Press is prohibited.

Be sure to visit the NYU Press Bookstore

[Design by NiceMedia]