Performance Analysis of Hill Cipher and Its Modifications

ABSTRACT: The history of cryptography goes to several thousand years back when ancient Egyptions tried to hide text by using unusual hieroglyphs instead of more ordinary ones here and there on a tablet. Although lot of cryptographic algorithms have been developed and practically used in various areas, the choice of best algorithm is still on focus of researchers. Since encryption/decryption is an expensive operation, the researchers have always tried to compromise between performance measured in terms of time-effectiveness and confidentiality (or secrecy) provided by cryptographic algorithms. The researchers have realized that the best cryptographic algorithm is determined by reasonable trade-off between performance and confidentiality of the cryptosystem. In this thesis we investigate performance of three cryptographic algorithms, namely Hill cipher, affine Hill cipher and Saeednia‟s modification. We perform comparative analysis of aforesaid cryptographic algorithms via measuring run times on different sized problems. Computer experiments are performed in MATLAB, a high-level technical computing language and interactive environment for algorithm development. Keywords: Cryptography, Hill cipher, affine Hill cipher, Saeednia‟s algorithm, linear transformation, permutation matrix. …………………………………………………………………………………………………………………………