Decrypting the Hill Cipher by Integer Programming

Date(s) - 05/02/2021
16:00 - 18:00

Categories No Categories

Deniz Akkaya, Bilkent University, IE

Time: February 5, 16:00

Zoom Meeting ID: 666-413-1670
Zoom Password: 606848

Abstract: The Hill Cipher is one of the older methods in classical cryptography based on linear algebra over finite fields. It was invented by Hill as a practical algebraic method for larger block sizes. The method heavily depends on the invertibility of linear transformations over finite modulo spaces, therefore it can be considered as a recovery process over matrices contained in the general linear group.

The Hill Cipher encryption method of cryptology is revisited in particular with a view towards dealing with noisy observations. A method based on integer programming is given for decrypting the Hill Cipher for both noiseless and corrupted observations. Exact formulations and suitable relaxations are discussed. Equivalence with existing methods and convergence guarantees are shown.

Bio: Deniz Akkaya is an M.Sc. student in Industrial Engineering Department at Bilkent University, working on the Optimization of Robust Loss Functions with Combinatorial Constraints and their applications in Compressed Sensing.