Practical assigment


Create a security module, which functions are used to create secured socket connection between two computers. Implement also an communication application that uses your module.

Returning of the assignment

Return the source code tarred and gzipped to lecturer vie email with subject line “[Ti5318800] practical assignment”. Reserve a time from lecturer beforehand for demonstrating your assignment to the lecturer. Prepare to answer to some question concerning your work. Deadline for returning the assignment is January 31 2008.

Content of assignment

Choose the security methods for your assignment based on the model below: Key exchange for symmetric key Use the first letter of your surname

  • A-J: Diffie-Hellman
  • K-M:Shamir three pass protocol
  • O-Ö:ElGamal

Symmetric cipher Last digit of your student number

  • 1-2:Triple DES
  • 2-3:SAFER
  • 3-4:BLOWFISH
  • 5-6:AES
  • 7-8:SEAL
  • 9-0:ARC4

Digital Signature second to last digit of your student number

  • 1-3: RSA
  • 4-6: DSA
  • 7-0: Elliptic curves (ECDSA)

Hash funktion Calculate the digits of your student number and take modulus 3 For example 4828 →(4+8+2+8)mod 3 → 1

  • 0:SHA
  • 1:MD5
  • 2:RIPEMD

If you wish to use some other algorithms, contact the lecturer.

You can use existing cryptolibraries in your work. Though one of the security methods have to be done by yourself. You can use any programming language you like, but remember that you have to be able to demonstrate that your code works.


Menezes, van Oorschot, Vanstone: Handbook of applied cryptography

Last modified: 2013/07/01 14:42