DES Design Controversy Originally designed to be efficient in hardware. A lot of money has been invested in hardware although DES standard is public there was considerable controversy over design in choice of 56-bit key(vs Lucifer 128-bit) and because design criteria were classified subsequent events and public analysis show in fact design was appropriate DES has become widely used, especially in financial applications4 DES Design Controversy • Originally designed to be efficient in hardware . A LOT of money has been invested in hardware. • although DES standard is public there was considerable controversy over design – in choice of 56-bit key (vs Lucifer 128-bit) – and because design criteria were classified • subsequent events and public analysis show in fact design was appropriate • DES has become widely used, especially in financial applications