As reported by Computerworld, Musicrypt is using BioPassword's multifactor authentication software to secure its promotional music deliveries:
"During the War, the allies discovered a way to track German telegraph operators by identifying their particular style of typing code, something known as 'the fist of the sender.' Forty years later, researchers SRI International, a nonprofit research institute spun out of Stanford University, applied this work to the keyboard and found that people could also be identified by the rhythm of their typing.
This technology eventually landed in the hands of BioPassword Inc., based in Issaquah, Washington. After taking about nine samples of an 8- to 16-keystroke password, the company's software is able to identify the 'fist' of the typist."
Update 2006/04/17: I forgot to mention that I initially heard of the fist of the sender in The Code Book by Simon Singh, which gives a good historical perspective on cryptography.
