Fortezza is an information security system based on a PC Card security token. Each individual who is authorized to see protected information is issued a Fortezza card that stores private keys and other data needed to gain access. It contains an NSA-approved security microprocessor called Capstone (MYK-80 ) that implements the Skipjack encryption algorithm.

Fortezza was developed for the U.S. Government's ill-fated Clipper chip project, but is widely used by the U.S. Government. The original Fortezza card (KOV-8) is a Type 2 product which means in cannot be used for classified information. A newer version called Fortezza Plus (or KOV-14) uses a Krypton microprocessor that implements stronger, Type 1 encryption and may be used for information classified up to TOP SECRET.

The Fortezza Plus card is used with NSA's Secure Terminal Equipment voice encryption systems that are replacing the STU-III. It is manufactured by the Mykotronx Corporation and by Spyrus. Each card costs about $240 and are commonly used with card readers sold by Litronic , a division of Saflink .