Widespread use of cryptography can mean trouble for law enforcement and security personnel when crooks and spies use cryptography to secure their communications from wiretapping. Under U.S. law, communications utilities are required to provide law enforcement access to communication links when proper judicial process has been observed. Such access is useless if the messages they provide access to are encrypted with powerful security.
For years the U.S. and other countries have tried to control the spread of cryptographic technologies, with little success.
What should public policy be with regard to free use of cryptographic systems? What can realistically be done to implement restrictive policies?