Assignment 2

Problems

Problem 1: Cryptanalysis (in the lab)

Download this file (cipher1.txt) and find the cipher-text assigned to your group. Perform cryptanalysis to (1) identify the cipher used to encrypt the data, (2) find the encryption key, and (3) decrypt the text. Submit a report that contains the following:

  1. (2 points) The recovered plain text (exactly as recovered, no need to add spaces or punctuation)
  2. (2 points) The name of the cipher,
  3. (2 points) The key, and
  4. (2 points) A brief description of the steps you took for recovering the key, including a (Github) link to any code you developed to solve the problem.

Problem 2: Cryptanalysis (at home)

First, familiarize yourself with the Playfair cipher by watching the videos below:

    1. Playfair Cipher video.
    2. Playfair Cipher mechanics.

Then, download this file (cipher2.txt) and find the cipher-text assigned to your group. The cipher-text is encrypted with Playfair. Your job is to find the encryption key, and then decrypt the text. Submit a report that contains the following:

  1. (5 points) The recovered plain text (exactly as recovered, no need to add spaces or punctuation)
  2. (2 points) a brief explanation of how one could infer that the text is encrypted with Playfair (in case it was not known),
  3. (3 points) the recovered key, and
  4. (7 points) a brief description of the steps you took for recovering the key (include a Github link to any code you developed to solve the problem).