Enhanced AES Algorithm using 512 Bit Key Implementation

In this technical world data are commuted through electronic media where data security is the major problem to be considered. In many cases multimedia applications require to satisfy many aspects of transmission. Reliable security of data is needed to protect data from unauthorized user. To ensure security, cryptography is the only way for secure data transmission. One such algorithm of cryptography is Advanced Encryption Standard algorithm commonly known as AES algorithm, a symmetric algorithm using the same key (private key) for encryption and decryption. AES algorithm is known for its resistance against the known attacks, its design simplicity, fast data processing and code compactness. But whoever has the key can read the message easily. The existing algorithm uses 128, 192 and 256 bits of key size. As the size of the key increases it is hard to decrypt the encrypted text. Therefore size of input and key are extended to 512 bits which ensures greater security. The number of rounds for processing the plain text is increased to 22, where the first 21 rounds perform all the four operations of the AES algorithm and the final round implements three of the four operations for encryption. Decryption is done by using the inverse operations of the encryption algorithm. AES-S will be suitable for applications with high security and throughput requirements without increasing the overall design when compared to original AES-128 bits. This project with expanded key of size 512 bits can also be enhanced to be used for encryption and decryption of images.