Abstract:
Information Security is essential when communicating over any untrusted medium and information system. When data are transmited over insecure communications channel, key is used to encrypt or decrypt data. The attacker tries to know that key which can transform the original form. So, the secure key is the most important in cryptographic system. This paper explains about to encrypt data using Diffie-Hellman key exchange algorithm for secure key. Diffie-Hellman algorithm depends on discrete logarithm to determine the key. After obtaining secure key, this key is used to encrypt or decrypt data with RC4 algorithm which is a key stream cipher algorithm requiring a secure exchange of shared key developed by Ronald Rivest of RSA. Diffie-Hellman is paid deep attention because it is one of the most common protocols used in networking today. Therefore, this algorithm is also used in banking system, military and communication to report proposal or important data.