Why did NIST select only one algorithm to propose for the AES?
NIST considered the possibility of selecting multiple algorithms for the AES, since that was a topic of discussion during the public evaluation periods. Many arguments were made both for and against the inclusion of multiple algorithms in the standard, and NIST’s AES selection team considered those comments prior to evaluating the algorithms. Briefly, NIST’s AES selection team decided to select only one algorithm for several reasons. First, other FIPS-approved algorithms (e.g., Triple DES) offer a degree of systemic resiliency, should a problem arise with the AES. Second, multiple AES key sizes provide for increased levels of security. Third, a single algorithm AES will promote interoperability and decrease the complexity of implementations that will be built to comply with the AES specifications, hopefully promoting lower implementation costs than a multiple algorithm AES. Fourth, a single AES algorithm addresses vendors’ concerns regarding potential intellectual property costs. 10.
