I need someone who has experience in Computer Security, to solve some questions as follow:
1- Download the file “plaintext.txt” found on the course home page. Add a secret message at
the end of the file, at least one page long, and the names of the student that created the file. Encrypt the updated file using your program (you may select any method you have
implemented). Post the encrypted file in the folder “Cipher texts”. The name of the file should
be the name of the student uploading the file.
2- In the folder mentioned above you will find cipher texts from the other students. Download
some of these and try to perform crypto analysis on them. You may use any tool or method to
perform this task. When you have successfully analysed at least one of the files, include a
description of how you did it in the report. (Extra credits if you can decrypt several files that
implemented different encryption algorithms).
3- Create a very simple hash function and implement it in Python (or Java). The hash
function should be able to accept input of different sizes and produce a hash value that is 8
4- Implement statistical tests of your hash function to test if it seems to be a good hash
function. You should at least run tests for Uniformity and that small changes in input still give
very different hash values. Consider using matplotlib to make it easy to analyse the result.
Uniformity can be tested with random input strings (both in terms of size and content). You
should test with at least a couple of thousand test strings.
To test the second property, you should again run at least 1000 tests with input strings that are
very similar (only differ in one bit) and investigate what distribution you get now for the hash
You can analyse the results manually or using different statistical tools, but you need to
discuss how well your function meet the different properties.
5- There is a difference between normal hash functions and secure has functions. What is
that difference? Prove that your hash function is not a secure hash function. What is the
easiest way to prove this?
If you feel you can solve it, send me a message here before you send anything on WhatsApp so I can check your profile first. Then I will provide you with the files that are needed to solve the assignment.
My price is fixed which is 20 EURO