Some types of satellite keys include BISS keys, Viaccess keys and Nagravision keys. Other keys, such as AES keys, Conax keys, and Constant Control World keys, are used less often by most consumers. BISS, which stands for Basic Interoperable Scrambling System, is a satellite scrambling system developed by the European Broadcasting Union to send news over a broadcasting satellite link used by TVNZ news reporters. Prior to the invention of BISS keys, unencrypted satellite feeds allowed anyone to view programming.
Cryptoworks keys is a DVB conditional access system that is used by many pay TV systems or free-to-watch systems throughout Europe. Like BISS keys, it is used to encrypt some feeds to cable television head ends. The coding systems in Cryptoworks is known to be very weak and can be hacked by computer enthusiasts.
AES keys are based on a design principle known as a substitution-permutation network, which is fast in both software and hardware terms. Unlike its predecessor, it works with Rijndael, which has a fixed block size of 128 bits and a key size of 128, 192 and 256 bits. AES keys use multiple rounds of repetition for differing encryption with each applicable amounts of bits, according to Satellit-key.ru.