Abstract: Cryptographic algorithms are used as fundamental techniques for assuring confidentiality and integrity of data used in financial transactions and for authenticating entities involved in the transactions. Secure data transmission via Internet or any public network, there is no alternative to cryptography. It is widely used by governmental and intelligence agencies around the world to safe transmission of any format of messages-online or offline. No data online is secure unless use any type of cryptography to send your messages. Cryptographic algorithm development is a never-ending race as the cryptanalysts are also getting smatter with the advent of higher computer power of decoding secret codes.. This research will concentrate on increasing the complexity of block cipher encryption. Secure key based Treble Data Encryption Standard algorithm (STDES) is based on secure keys of Static IP address. STDES algorithms ensure the improved encryption performance, high secure and less encryption, decryption time. STDES algorithm is highly secure while improving the efficiency of cryptography algorithm.

Keywords: Secure key, Static IP address, Encryption, Decryption, Permutation, S-box.