Modification of Symmetric-Key DES into Efficient Asymmetric-Key DES using RSA

In this paper, we propose a new approach for DES based on public key cryptography called Asymmetric-DES. Where hybrid of DES and RSA algorithm are combine and found to be secure for only two rounds, whereas symmetric DES is secure for sixteen rounds with different combination of key. Thus, we modified the structure of DES and applies RSA encryption on plaintext with the public key of receiver to obtain the cipher text. Similarly the modification is performed in decryption algorithm. As a result breaking of two-round asymmetric DES is hard problem, as its security depend on RSA algorithm.