A New Way to Design and Implementation of Hybrid Crypto System for Security of the Information in Public Network

In this paper, a new hybrid concept is proposed by analyzing the principle of the hybrid cryptography based on the combination of symmetric and message digesting. Moreover, the security and performance of the proposed concept will also estimate. In proposed concept we designed a new symmetric encryption algorithm and combine with SHA1 message digesting function to provide hybrid nature. Now the proposed system will try to improve exiting problem. In proposed system symmetric key will use series of logical functions like XOR, Circular Shift (Right, Left), Feastel function [6] and these operations are time efficient operation as compared to mathematical operation for providing confidentiality and authentication. For integrity, proposed system use SHA-1[15] algorithm. Due to this reason proposed system is efficient then existing system. The experimental results based on combination of symmetric and message digesting will approve the effectiveness of the proposed concept, and the combination of symmetric and message digesting will show large variation in key space and provide high-level security. The cipher text generated by this method will be approximately double in size as the plaintext, and will be suitable for practical use in the secure transmission of confidential information over the Internet. The purpose of hybrid cryptosystems is not to provide perfect or risk-free security. Rather, the purpose of cryptography-based security is to protect information resources by making unauthorized collection of the information or tampering with the information costly than the existing potential value that might be gained. Good hybrid cryptography, when properly implemented and used, makes attempts to violate security cost-prohibitive. Keywords-Encryption, Decryption, Security, Image,