Cryptology ePrint Archive: Report 2002/003

Square Attacks on Reduced-Round Variants of the Skipjack Block Cipher

Jorge Nakahara Jr and Bart Preneel and Joos Vandewalle

Abstract: This report surveys on a series of Square attacks on reduced-round versions of the Skipjack block cipher. {\bf Skipjack} is an iterated block cipher encrypting 64-bit plaintext blocks into 64-bit ciphertext blocks, using an 80-bit key. Its design is based on a generalized Feistel Network making up 32 rounds of two different types. This cipher was developed by the National Security Agency for the Clipper chip and Fortezza PC card.

Category / Keywords: secret-key cryptography / cryptanalysis, block ciphers

Date: received 4 Jan 2002, last revised 8 Jan 2002

Contact author: jorge nakahara at esat kuleuven ac be

Available format(s): Postscript (PS) | Compressed Postscript (PS.GZ) | BibTeX Citation

Note: Newest version with new revised complexity summary table at the end of the paper. It is a bit long, but fully-illustrated :-)

Version: 20020108:152420 (All versions of this report)

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