University of Virginia, Department of Computer Science
CS551: Security and Privacy on the Internet, Fall 2000

Manifest: Monday 6 September 2000
Assignments Due
Monday, 11 SeptemberProblem Set 1
Monday, 18 SeptemberProjects Preliminary Proposal

News
RSA Security released the RSA algorithm into the public domain today (the patent was due to expire on September 20th). See http://www.rsasecurity.com/news/pr/000906-1.html for the press release. We will cover RSA in two weeks.
Readings
Read before 11 September: Stallings, Chapter 4.1: Triple DES

Read before 13 September:

Optional reading for more information: (see web version for links)
Questions

DEAR SIR -- A favorable and a confidential opportunity offering by Mr. Dupont de Nemours, who is revisiting his native country gives me an opportunity of sending you a cipher to be used between us, which will give you some trouble to understand, but, once understood, is the easiest to use, the most indecipherable, and varied by a new key with the greatest facility of any one I have ever known. I am in hopes the explanation inclosed will be sufficient. Let our key of letters be [some figures which are illegible] and the key of lines be [figures illegible] and lest we should happen to lose our key or be absent from it, it is so formed as to be kept in the memory and put upon paper at pleasure; being produced by writing our names and residences at full length, each of which containing 27 letters is divided into two parts of 9. letters each; and each of the 9. letters is then numbered according to the place it would hold if the 9. were arranged alphabetically, thus [so blotted as to be illegible]. The numbers over the letters being then arranged as the letters to which they belong stand in our names, we can always construct our key. But why a cipher between us, when official things go naturally to the Secretary of State, and things not political need no cipher. 1. matters of a public nature, and proper to go on our records, should go to the secretary of state. 2. matters of a public nature not proper to be placed on our records may still go to the secretary of state, headed by the word `private.' But 3. there may be matters merely personal to ourselves, and which require the cover of a cipher more than those of any other character. This last purpose and others which we cannot foresee may render it convenient and advantageous to have at hand a mask for whatever may need it. But writing by Mr. Dupont I need no cipher. I require from him to put this into your own and no other hand, let the delay occasioned by that be what it will.

From Thomas Jefferson's letter to the U.S. Minister to France (Robert R. Livingston), Washington, Apr. 18, 1802.


CS 655 University of Virginia
Department of Computer Science
CS 551: Security and Privacy on the Internet
David Evans
evans@cs.virginia.edu