What is the Advanced Encryption Standard?
The Advanced Encryption Standard, abbreviated AES, is basically a block cipher adopted as an encryption standard. This symmetric key encryption technique will eventually replace the widely used DES (Data Encryption Standard). This Standard is also known as Rijndael and it features a very good combination of performance, flexibility, security, efficiency, and ease of implementation.
The Advanced Encryption Standard is a symmetric and iterative key block cipher that uses keys of 128, 192, and 256 bits. It can encrypt and decrypt data in blocks of 128 bits (16 bytes). It uses the same key to encrypt and decrypt the data.
Key AES features
It has outstanding key setup times and low memory requirements. The algorithm performs very good on many platforms and environments, in all possible modes. Its operations are very easy to defend against power and timing attacks.
The Advanced Encryption Standard algorithm basically uses three different key sizes. These are 128, 192, and 256 bit encryption keys. Each key forces the algorithm to behave in a different way, so increasing the key size will offer a larger number of bits with which to scramble the data, while increasing the complexity of the cipher algorithm.
The AES is far more powerful than its predecessor, the DES. DES-encrypted messages could be decrypted in just 56 hours back in 1998. From 2006, the only way to attack an AES implementation is with a side-channel attack.
The Advanced Encryption Standard was developed on big-endian systems so using it on little-endian systems causes a loss in efficiency. Considerable bit swapping must be applied to output the correct test vector results.
When both the encryptor and the decryptor are running on Windows XP or later operating systems, the use of Rijdael algorithm is highly advised. For older systems, using Triple DES is recommended.
Key Exam Points
- Understand how the Advanced Encryption Standard works
- For the exam study examples of the AES algorithm that help you gain a ferm grip of this topic
- Take Exam 70 536 Exam tests about this topic
Related Terms
This article is based on the 2nd edition of the Microsoft .Net Framework Application Training Kit with the purpose to help 70-536 Exam takers to succeed. I constantly look for ways to improve the content. Please leave a comment about this article or drop me a message if you would like to see changes for this site.
