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This article examines how effectively Britain secured its diplomatic communications against hostile decryption during the early Cold War. It shows that between 1945 and 1970 the Foreign Office and the Commonwealth Relations Office introduced and operated four advanced cipher machines, Typex, Rockex, Noreen and Alvis, which produced very strong ciphers. However, Britain did suffer physical compromises of Rockex through Soviet espionage and an attack on the British embassy in Beijing. Rockex was also vulnerable to technical surveillance of its acoustic and Tempest emissions, and the Soviets exploited this to read the encrypted communications of the British embassy in Moscow. [ABSTRACT FROM AUTHOR]

A Spanish strip cipher, known as the "PILAR key", has been reconstructed from a set of encrypted telegrams sent by the General Directorate of Security in Madrid, Spain, to the civil government in Málaga, Spain, in 1940 after the Spanish Civil War. The reconstruction of this unrecorded key is based on the application of a cyclic rotation model to the strip cipher behavior, allowing one to recover the homophone table and the mobile strip. In this way, the messages are correctly deciphered and the PILAR key is now part of the large list of known Spanish strip ciphers. [ABSTRACT FROM AUTHOR]

The article explains the communication and encryption processes of the JN-25 cipher of the Imperial Japanese Navy. Topics discussed include the role of JN-25 in concealing commands and operations of the Japanese fleet during World War II, decryption process on the cipher through a codebook and a book of random numbers, and the use of the jiggling method in cracking JN-25.

This article gives a historical overview of the various design criteria of the Data Encryption Standard (DES) and some of its variants, starting from the legendary conditions given by Coppersmith in 1994. The authors follow their development until now, as simplified DES-like ciphers exist with improved properties. While doing so, they analyze the properties imposed on the S-boxes and the permutation used in the round function, and explain implications on the resistance of these ciphers against differential and linear cryptanalysis. [ABSTRACT FROM PUBLISHER]

In this article, the author demonstrates that cracking the Soviet VIC cipher is possible if one knows the enciphering algorithm. Without this knowledge, the VIC cipher appears to be very strong, and it is almost impossible to crack a single message encrypted with it. [ABSTRACT FROM PUBLISHER]

The Hagelin M-209 portable encryption device was used by the U.S. Army in World War II and the Korean War, as well as by other armies and in embassy settings. In this article, a fully automated, computerized known-plaintext attack is presented. It is based on hillclimbing and a novel fitness function: the aggregate displacement error. Performance evaluation shows that this attack is able to recover key settings for messages as short as 50 characters. To validate these results, several publicly available challenge messages were solved with this method, including a message with only 40 letters. [ABSTRACT FROM PUBLISHER]

Several modes of operation have been built upon block cipher security. Among them, CFB is considered to be one of the popular modes of operation because of its self-synchronizing property. Besides, appearance of OCFB makes CFB even more competitive. However, because of the stalling problem (i.e., there is a need to stall while doing block encryption) and the inability to arrange the keystream in advance, both the CFB and OCFB modes are considered to be inadequate for such real-time applications, where the appearance of inputs is expected to be uniform. In this article, researchers present a new mode of operation based on the underlying foundation of both the CFB and OCFB modes of operation, called real-time based optimized cipher feedback mode (RT-OCFB), which remedies this problem. They also argue that the proposed mode of operation (RT- OCFB) holds the similar imperative security properties as CFB and OCFB, which are indeed essential for modern cryptography. [ABSTRACT FROM PUBLISHER]

This work is a study of DES-like ciphers where the bitwise exclusive-or (XOR) operation in the underlying Feistel network is replaced by an arbitrary group operation. The authors construct a two-round simplified version of DES that contains all the DES components and show that its set of encryption permutations is not a group under functional composition, it is not a pure cipher, and its set of encryption permutations does not generate the alternating group. They present a non-statistical proof that forn ≤ 4 the set ofn-round Feistel permutations over an arbitrary group do not constitute a group under functional composition. [ABSTRACT FROM PUBLISHER]

The 2014 edition of the biannual Charlotte International Cryptologic Symposium featured interesting talks and a notable cipher equipment exhibition. Apparently, this symposium has established itself as the second regular crypto history event besides the NSA Cryptologic History Symposium, which also takes place on a biannual basis. This means that one can expect an important crypto history symposium per annum for the years to come. [ABSTRACT FROM PUBLISHER]

GOST is a well-known Russian encryption standard. Until 2010, no researcher found a single-key attack on GOST. In 2010, GOST was submitted to ISO 18033 to become a worldwide industrial encryption standard. Since 2011, many attacks on GOST faster than brute force have been found [3, 4, 5, 10, 12]. By default, GOST has 256-bit keys. However, in many applications 128-bit keys are required. The authors should note that GOST is an exceptionally economical cipher in implementation: Even as a 128-bit cipher, GOST requires about four times less gates to implement than AES-128 (see [16]). There are two very natural 128-bit variants of GOST: Either the same 128-bit key is repeated, or it is repeated with inversion of the 32-bit words. Both variants are natural simplified variants fully compliant with the standard which have already been considered as potentially interesting targets for advanced slide attacks [2]. In this article, the authors show that both these variants are insecure. All of their attacks are nearly practical. [ABSTRACT FROM PUBLISHER]