Prof. Avelino Zorzo -
School of Engineering PUCRS Students: Marco Goedert

For the first assessment of the course, the objective is to create a program that, given a cipher text, finds the plain text.

In this assessment, you must first discover the size of the key that was used to encrypt the plain text. For this, one of two methods can be used: Kasiski Test or Index of Coincidence.

The text can be in Portuguese or English.

The frequency tables of letters in Portuguese/English can be found at: https://en.wikipedia.org/wiki/Letter_frequency.

Write a two-page report explaining how the cryptanalysis was done and part of the cipher text and plain text.

Submit the source code (in any programming language) and the report written in the ACM, IEEE, or SBC article format.

The assessment will be evaluated as follows: algorithm for automatic calculation of key size (2 points), algorithm for deciphering the text (2 points), complete solution (2 points), text (in the requested format) describing the solution (2 points), code (2 points).

The source code and the article must be submitted through Moodle.

GOOD WORK.

20201-teste1.txt => text in English 20201-teste2.txt => text in Portuguese