> It has been said that the US National Security Agency (NSA) blocked the implementation of encryption in the TCP/IP protocol for the original ARPANET, because it wanted to be able to listen in on the traffic that crossed that early precursor to the internet.
Citation needed! I've never heard that story, and I've read much of what has been written on the history of modern encryption.
According to Paul Lambert and Howard Weiss , NSA actually sponsored development of encryption for ARPANET.
N.B. NSA certainly tried to prevent widespread encryption several times during the 1990's, so I wouldn't be surprised if they did block encryption in TCP/IP, but unless you have some evidence that they did, or at least you can say who told you this rumor, then why publish it?