1.4. The problem with politics

Computer cryptography has been, and to some extent continues to be, dogged by two particular legal/political issues:

This has lead to all sorts of oddities. For example, it is quite common to find that cryptographic software has been deliberately developed in countries other than the US, both to avoid export restrictions and to avoid problems with patents. It is also still common to come across references to "Export Grade" ciphers (weak ciphers that were permitted to be exported before 1999), or "US domestic grade" ciphers (all the rest). Additionally some cryptographic protocols use what can seem to be unusual algorithms to avoid patent restrictions.