Today the greatest challenge to the cyber world is security. Technology rapidly changes, making old methods obsolete and requiring new developments and advancements in information security. Cryptography, the science of preparing coded or protected communications, designs systems which make messages intelligible only to the person possessing a key. There are two types of key-based cryptosystems: symmetric key and asymmetric cryptosystem. Symmetric key encryption is a cryptographic technique that uses a shared secret key to encrypt and decrypt data. Symmetric encryption algorithms are very efficient in processing large amounts of information. There are two types of symmetric encryption algorithms: stream ciphers and block ciphers, which provide bit-by-bit and block encryption respectively. The Advanced Encryption Standard (AES) is a block cipher which was approved by the U.S. Federal Information Processing Standards in 2001 and is used to secure Top Secret information by the federal government. This cryptosystem has a highly complex algebraic structure. We design a simplified version of this cryptosystem that has all the functions that AES has, but is made suitable for timely security analysis. Our simplified AES is based on a field of characteristic 7, while all other known versions of AES are based on fields of characteristic 2. We then investigate how the characteristic of the field affects the security of this cryptosystem.
Craig, Suzanne, "A Simplified AES with Field Characteristic 7" (2014). College of Arts and Sciences Presentations. Paper 33.