Cryptology ePrint Archive: Report 2017/440

Cryptographic Security Analysis of T-310

Nicolas T. Courtois and Klaus Schmeh and Jörg Drobick and Jacques Patarin and Maria-Bristena Oprisanu and Matteo Scarlata and Om Bhallamudi

Abstract: T-310 is an important Cold War cipher. It was the principal encryption algorithm used to protect various state communication lines in Eastern Germany throughout the 1980s. The cipher seems to be quite robust, and until now, no cryptography researcher has proposed an attack on T-310. In this paper we provide a detailed analysis of T-310 in the context of modern cryptography research and other important or similar ciphers developed in the same period. We introduce new notations which show the peculiar internal structure of this cipher in a new light. We point out a number of significant strong and weak properties of this cipher. Finally we propose several new attacks on T-310.

Category / Keywords: secret-key cryptography / Cold War, block ciphers, T-310, unbalanced compressing Feistel ciphers, Differential Cryptanalysis, Linear Cryptanalysis, slide attacks, self-similarity attacks, ciphertext-only attacks

Original Publication (with major differences): extended version of several papers published elsewhere

Date: received 20 May 2017, last revised 26 Jun 2017

Contact author: n courtois at bettercrypto com

Available format(s): PDF | BibTeX Citation

Version: 20170626:205002 (All versions of this report)

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