Efficiency in software: NIST-specified platform 200 MHz Pentium pro, Borland C++ Speed Mbits/s H128-bit key 192-bit key 30 256-bit key 25 0 15 10 Rijndael Rc6 Twofish Mars Serpent11 0 5 10 15 20 25 30 Rijndael RC6 Twofish Mars Serpent Efficiency in software: NIST-specified platform 128-bit key 192-bit key 256-bit key 200 MHz Pentium Pro, Borland C++ Speed [Mbits/s]