An Enhanced and Secured RSA Public Key Cryptosystem Algorithm Using Chinese Remainder Theorem

The public key cryptosystems are mainly used to provide two cryptographic services called confidentiality and authentication. The RSA is one well known and widely used public key cryptosystem that uses two large and distinct integers to generate the keys. In this paper, we proposed an enhanced and secured RSA public key cryptosystem (ESRPKC) algorithm using Chinese remainder theorem. To increase the complexity of the system the proposed ESRPKC uses four prime numbers instead of two primes to generate the public/private key pairs. To generate the public/private key pairs, the proposed ESRPKC uses similar method as that of traditional RSA. In order to enhance the security level, the encryption and decryption functions are modified in proposed ESRPKC. The encryption function uses one extra key parameter called encryption key which is generated by using Chinese remainder theorem. The decryption function also uses one extra parameter to decrypt the message. The complexity of encryption and decryption functions is also acceptable. The proposed algorithm requires only one extra multiplication to perform encryption and decryption operations as compare to traditional RSA cryptosystem. The proposed scheme is highly secured because the encryption and decryption functions uses one extra key parameter and are not only dependent on the public and private key pairs respectively. The security and performance analysis ensures that the proposed ESRPKC algorithm is highly secure and efficient as compare to existing schemes.