Verifying the kernel—known as the seL4 microkernel—involved mathematically proving the correctness of about 7,500 lines of computer code in an project taking an average of six people more than five years.
http://www.schneier.com/blog/archives/2009/10/proving_a_compu.html
...the wire. A hacker could certainly sniff the password from the wire, but it is now useless. Example: The original OTPsystem was named "S/Key"; a term trademarked by Bellcore. The idea was to create a password authentication system that...
http://oss.sgi.com/LDP/LDP/Linux-Dictionary/html/o.html