AES or Advanced Encryption Standard is a symmetric cryptography and taken as standard by National Institute of Standards and Technology (NIST) for encryption. If you want to know more on Encryption and Decryption you can read this linked article or if you want see one application of AES or Advanced Encryption Standard, you can read this article on SSL.
What is AES or Advanced Encryption Standard ?
Joan Daemen and Vincent Rijmen are the two person who developed and submitted the method of AES or Advanced Encryption Standard. Rijndael algorithm has a variable block size of 128, 192 or 256 bits and a variable key length of 128, 192 or 256 bits. This a very high level of security. AES limits the block length to 128 bits, while the choice of key length of 128, 192 or 256 bits has been reproduced unchanged. The names of the three AES variants are AES-128, AES-192 and AES-256 and are related to the selected key length. The algorithm is freely available and can be used without licensing fees and implemented in software and hardware. By the use of the AES the encryption stanadard Data Encryption Standard (DES) is developed, which is the most widely used symmetric algorithm to encrypt data.
Further Notes on AES or Advanced Encryption Standard
Rijndael Key Shedule is a block cipher. A block length and key length independently can have the values of 128, 160, 192, 224 or 256 bits while AES restricts the fixed block size of 128 bits and a key size of 128, 192 or 256 bits. Each block is like a two-dimensional table written with four rows whose cells represents bytes in size. The number of columns thus varies depending on the block size of 4 (128 bits) to 8 (256 bits). Each block is then subjected to sequentially specific transformations by the implementation. In various complex methods we can do this encryption.
In the decryption, data is proceeded exactly backwards. AES is the encryption standard for wireless LAN and its Wi-Fi equivalent, WiMAX as well in SSH, IPsec, IP telephony and SRTP. Mac OS X uses AES standard encryption method for disk images. In addition, the algorithm is used for encryption of various compressed file archives like 7-Zip and RAR.