The results of fast implementations of all five AES final candidates using Virtex Xilinx Field Programmable Gate Arrays are presented and analyzed. Performance of several alternative hardware architectures is discussed and compared. One architecture optimum from the point of view of the throughput to area ratio is selected for each of the two major types of block cipher modes. For feedback cipher modes, all AES candidates have been implemented using the basic iterative architecture, and achieved speeds ranging from 61 Mbit/s for Mars to 431 Mbit/s for Serpent. For non-feedback cipher modes, four AES candidates have been implemented using a high-throughput architecture with pipelining inside and outside of cipher rounds, and achieved speeds ranging from 12.2 Gbit/s for Rijndael to 16.8 Gbit/s for Serpent. A new methodology for a fair comparison of the hardware performance of secret-key block ciphers has been developed and contrasted with methodology used by the NSA team.