Capstone (cryptography)
Encyclopedia
Capstone is the name of a United States
government long-term project to develop cryptography
standards for public and government use. Capstone was driven by the NIST and the NSA
; the project began in 1993. The initiative involved four standard algorithms: a data encryption algorithm called Skipjack
, along with the Clipper chip
that included the Skipjack algorithm, a digital signature algorithm, DSA
, a hash function, SHA-1, and a key exchange
protocol. Captstone's first implementation was in the Fortezza
PCMCIA card.
The initiative encountered massive resistance from the cryptographic community, and eventually the US government abandoned the effort. The main reasons for this resistance were concerns about Skipjack
's design, which was classified
, and the use of key escrow
in the Clipper chip.
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
government long-term project to develop cryptography
Cryptography
Cryptography is the practice and study of techniques for secure communication in the presence of third parties...
standards for public and government use. Capstone was driven by the NIST and the NSA
National Security Agency
The National Security Agency/Central Security Service is a cryptologic intelligence agency of the United States Department of Defense responsible for the collection and analysis of foreign communications and foreign signals intelligence, as well as protecting U.S...
; the project began in 1993. The initiative involved four standard algorithms: a data encryption algorithm called Skipjack
Skipjack (cipher)
In cryptography, Skipjack is a block cipher—an algorithm for encryption—developed by the U.S. National Security Agency . Initially classified, it was originally intended for use in the controversial Clipper chip...
, along with the Clipper chip
Clipper chip
The Clipper chip was a chipset that was developed and promoted by the U.S. National Security Agency as an encryption device to be adopted by telecommunications companies for voice transmission...
that included the Skipjack algorithm, a digital signature algorithm, DSA
Digital Signature Algorithm
The Digital Signature Algorithm is a United States Federal Government standard or FIPS for digital signatures. It was proposed by the National Institute of Standards and Technology in August 1991 for use in their Digital Signature Standard , specified in FIPS 186, adopted in 1993. A minor...
, a hash function, SHA-1, and a key exchange
Key exchange
Key exchange is any method in cryptography by which cryptographic keys are exchanged between users, allowing use of a cryptographic algorithm....
protocol. Captstone's first implementation was in the Fortezza
Fortezza
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...
PCMCIA card.
The initiative encountered massive resistance from the cryptographic community, and eventually the US government abandoned the effort. The main reasons for this resistance were concerns about Skipjack
Skipjack (cipher)
In cryptography, Skipjack is a block cipher—an algorithm for encryption—developed by the U.S. National Security Agency . Initially classified, it was originally intended for use in the controversial Clipper chip...
's design, which was classified
Classified information
Classified information is sensitive information to which access is restricted by law or regulation to particular groups of persons. A formal security clearance is required to handle classified documents or access classified data. The clearance process requires a satisfactory background investigation...
, and the use of key escrow
Key escrow
Key escrow is an arrangement in which the keys needed to decrypt encrypted data are held in escrow so that, under certain circumstances, an authorized third party may gain access to those keys...
in the Clipper chip.