General Instructions. Students are required to work in groups of 2 or 3 for this assignment. An assignment submitted on behalf of a "group" having only one student will receive a grade of F. All members of the group are responsible for understanding the entire assignment.
No late assignments will be accepted.
Academic Integrity. Collaboration between groups is prohibited and will be treated as a serious violation of the University's academic integrity code.
The Assignment. Choose and submit a solution for only one of the following cipher-breaking exercises. In each, you are given enciphered English text and a hint about the encryption algorithm that was used. Your mission: Develop (or find on the web) the necessary (software) tools. Then, use them to help you produce plaintext.
Grading. The exercises that follow appear in increasing order of difficulty--the first is the easiest and the last is the most difficult. Which (single) exercise you submit determines your grade on this assignment. (Try as many of the exercises as you like, but hand-in only one.)
|U||(Unsatisfactory) Submitted work is not indicative of a "good faith" attempt to solve any exercise.|
|GF||(Good Faith Attempt) Submitted work is indicative of a "good faith" attempt to solve one of the exercises.|
|G||(Good) The correct plaintext for exercise 1 was derived, and the manner in which it was derived is cryptoanalytically justified (i.e., guessing is not good enough) and adequately documented.|
|B||(Better) The correct plaintext for exercise 2 was derived, and the manner in which it was derived is cryptoanalytically justified (i.e., guessing is not good enough) and adequately documented.|
|VG||(Very Good) The correct plaintext for exercise 3 was derived, and the manner in which it was derived is cryptoanalytically justified (i.e., guessing is not good enough) and adequately documented.|
|E||(Excellent) The correct plaintext for exercise 4 was derived, and the manner in which it was derived is cryptoanalytically justified (i.e., guessing is not good enough) and adequately documented.|
The text was enciphered using a monoalphabetic substitution cipher. Blank spaces and punctuation have not been altered.
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Submission Procedure. Create a file containing your solution. Call this file xxxxx0, where xxxxx is the Cornell network id of the team member whose net id is alphabetically smallest of your team. Then copy this directory to the following folder:
Don't be disturbed by warnings informing you that the file cannot be accessed after it has been copied.
Should you wish to revise your submission after you have copied it to our folder, then simply correct the files and recopy the entire directory---but this time use the name xxxxx1. Revisions to that should be named xxxxx2, and so on. We will grade only the largest-numbered file of a series.
What to Hand In. Not only should you submit plaintext but also submit documentation to justify your solution. This documentation should describe the strategy you employed, show the details for each of the steps of that strategy, show listings for any programs you wrote, show the output of these programs, and show how you transformed that output into your solution.
Needless to say, you may find it easiest if the "file" that you submit is, in fact, a directory. If you do submit a directory, then make sure it contains a README file that describes what other files the grader should read and in what order they should be read.