Cryptology ePrint Archive: Report 2013/592

Cryptanalysis of the Toorani-Falahati Hill Ciphers

Liam Keliher and Anthony Z. Delaney

Abstract: In 2009 and 2011, Toorani and Falahati introduced two variants of the classical Hill Cipher, together with protocols for the exchange of encrypted messages. The designers claim that the new systems overcome the weaknesses of the original Hill Cipher, and are resistant to any ciphertext-only, known-plaintext, chosen-plaintext, or chosen-ciphertext attack. However, we describe a chosen-plaintext attack that easily breaks both Toorani-Falahati Hill Ciphers, and we present computational results that confirm the effectiveness of our attack.

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

Original Publication (in the same form): IEEE Symposium on Computers and Communications (ISCC 2013)

Date: received 12 Sep 2013

Contact author: lkeliher at mta ca

Available format(s): PDF | BibTeX Citation

Version: 20130914:224314 (All versions of this report)

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