Abstract:
Nowadays, public-key cryptography, especially Rivest-Shamir-Adleman (RSA), is becoming more
and more crucial for e-commerce transactions. Several digital consumer appliances, such as set-
top boxes and smart cards, may now send and receive many RSA-encoded messages. However,
due to the exponentiation and multiplications of very large numbers, the RSA algorithm is inappropriate
for encrypting large messages. Hence to fill this gap, this thesis work proposes an efficient modular
exponentiation technique for the RSA cryptosystem which can enhance the execution speed of the
standard RSA cryptosystem by applying the square-multiply technique of exponentiation. The
MATLABR2019a programming platform is employed for the actual implementation of this study.
The proposed work discusses the Standard RSA (SRSA) and Modified RSA (MRSA) cryptographic
algorithms by considering different performance evaluation metrics such as encryption time,
decryption time, memory usage, throughput, and avalanche effect through a practical
implementation using MATLAB. Concerning the encryption and decryption time performance, the
MRSA algorithm outperforms the SRSA algorithm by 17.46442% and 18.70409%, respectively.
Moreover, the MRSA has a 14.53511% higher avalanche value than the SRSA, showing its greater
security. Also, it outperforms the SRSA algorithm in terms of encryption and decryption
throughput by 15.80883% and 15.12928% respectively. However, because the MRSA algorithm
uses an array list, which uses more memory than the SRSA, it consumes slightly more memory
(1.05849%) overall.
