The United States classifies encryption software as "munitions", in order to restrict its export.  This hinders the development of e-commerce, and open source network software.

Here are some relevant links.

The mozilla crypto FAQ

Some software links:

• PGP (Pretty Good Privacy)
• GPG (Gnu Privacy Guard)
• The classic example: "RSA in 3 lines"

The Electronic Frontier Foundation (EFF)
        The Bernstein (aka "snuffle") case
        EFF Archives: [ by category ] [ full index ]

RSA Labs' crypto FAQ

The "snake oil FAQ"

Swedish University Network's tools.

The Wassenar arrangement (and its flashy home page)