Maki Shigeri

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This paper presents the results of applying an attack against the Data Encryption Standard (DES) implemented in some applications, using side-channel information based on CPU delay as proposed in [11]. This cryptanalysis technique uses side-channel information on encryption processing to select and collect effective plaintexts for cryptanalysis, and infers(More)
This paper reports impossible differential cryptanalysis on the 128-bit block cipher CLEFIA that was proposed in 2007, including new 9-round impossible differentials for CLEFIA, and the result of an impossible differential attack using them. For the case of a 128-bit key, it is possible to apply the impossible differential attack to CLEFIA reduced to 12(More)
This paper reports impossible differential cryptanalysis on the 128-bit block cipher CLEFIA that was proposed in 2007. It is known that there are the 9-round impossible differentials in CLEFIA. This paper presents the several results of impossible differential attacks using multiple impossible differentials. For key lengths of 128, 192 and 256 bits, it is(More)
This paper reports the greater bias found in the output sequence of VMPC, a modified RC4 stream cipher proposed in 2004. Using the bias with approximately 2 output bytes allows us to distinguish VMPC from truly random sequence. Distinguishing attack can also break RC4A, an algorihm based on RC4, more efficiently than any existing attacks. With about 2(More)
LILI-128 is the stream cipher proposed as a candidate cipher for the New European Schemes for Signatures, Integrity, and Encryption (NESSIE) Project. Some methods of breaking it more efficiently than an exhaustive search for its secret key have been found already. The authors propose a new method, which uses shorter bit sequence to break LILI-128(More)
A concrete attack using side channel information from cache memory behaviour was proposed for the first time at ISITA 2002. The attack uses the difference between execution times associated with S-box cache-hits and cache-misses to recover the intermediate key. Recently, a theoretical estimation of the number of messages needed for the attack was proposed(More)
This paper describes the attack on SOSEMANUK, one of the stream ciphers proposed at eSTREAM (the ECRYPT Stream Cipher Project) in 2005. The cipher features the variable secret key length from 128-bit up to 256-bit and 128-bit initial vector. The basic operation of the cipher is performed in a unit of 32 bits i.e. “word”, and each word generates keystream.(More)