The History of the Development and the Analysis of the Cipher Machine T-310/50 and the Procedure ARGON by the ZCO

Abstract

This paper describes important aspects of the 10 years of development and the 18 years of security analysis of the cipher machine T-310/50 and the procedure ARGON by the Central Cipher Authority of the GDR. The threat model of the analysis is pictured. Examples of the security analysis of the cipher algorithm, machine, procedure and key management are provided. The focus is on the analysis of the operating functions of the T-310/50 (operating analysis), including the analysis of operating errors, as well as the analysis of the instruction manual for the cipher procedure ARGON. The possibilities of obtaining information by an attacker from traffic reconnaissance in general and decryption attacks in particular are assessed.