William Friedman , often referred to as the Father of American Cryptology, was interested in a wide range of cryptologic topics. He developed several practical designs to protect critical communications.

Featured here is a device he invented and dubbed "Cryptest". It is a cylindrical-type check-authenticator. Friedman intended the device to be used for both commercial and military applications. Cryptest was formally patented on 15 August 1950 and acquired for the NSA Museum on 3 March  1954.

 An NCM exhibit.  (Photo by Ralph Simpson)

Contributors and Credits:

1) Ralph Simpson <ralphenator(at)>
2) NCM placard

Back To Menu Page

Apr 20/12