The
United States Postal Service (USPS) processes over 200
billion pieces of mail each year. Approximately 25 percent of that
mail uses printed metered stamps, or indicia. Ensuring the
protection and accurate accounting of those indicia is
a problem solved through cryptography.
This exhibit, courtesy of Pitney Bowes, shows some of the history of cryptography in metered mail. In 1920, the USPS permitted the first use of indicia and Pitney Bowes produced a system that securely stored, accounted, and dispensed postage through its postage meter machine. In 1979, the first commercial application of remote transaction systems was introduced. It used a meter-specific one-time pad that was physically implemented as code on mylar tape. Today, digital signature and message authentication code are used to ensure integrity and authenticity of indicia information. The indicia information is encoded by a two-dimensional bar code. The 2D barcode encodes unique indicium and digital signature information to ensure integrity and authenticity.
This display stands as one example of how cryptology plays a role in everyday life and is not solely the auspices of the government and military.