NASA Scientific and Technical Aerospace Reports

using a value of higher order differential which holds with probability. The success of attack depends on the probability,
however, the necessary number of chosen paintext and computational cost become very small. ICEBERG is a block cipher
with sixteen round SPN structure. In this paper, we analyze its higher order differential property, and estimate its strength
against higher order differential attacks. As a result, we found that five round ICEBERG is attackable using eighth order
differential with 2,304 chosen cipher texts and 2(sup 85) times round function calculations. And in the case using probabilistic
seventh order differential, it is attackable with 1,152 chosen cipher texts and 283 times round function calculations and
probability about 0.7.
Author
Cryptography; Differential Equations; Algorithms; Reconfigurable Hardware
20060002083 National Inst. of Information and Communications Technology, Tokyo, Japan
Error Detection and Authentication in Quantum Key Distribution
Yamamura, Akihiro; Ishizuka, Hirokazu; Journal of the National Institute of Information and Communications Technology.
Special Issue on Information Security, Volume 52, Nos. 1/2; March/June 2005, pp. 141-151; In English; See also
20060002073; Copyright; Avail.: Other Sources
Detecting errors in a raw key and authenticating a private key are crucial for quantum key distribution schemes. Our aim
is to propose practical methods for error detection and authentication in quantum key distribution schemes. We introduce
several concepts about neighborhood collision free properties of Boolean functions, which are closely related to hash
functions, and propose methods based on neighborhood collision free functions and error correcting codes such as
Reed-Solomon code. We also examine whether or not widely used cryptographic hash functions SHA-1 and MD5 satisfy the
neighborhood collision free property by computation experiments.
Author
Computer Information Security; Error Correcting Codes; Quantum Cryptography
20060002084 National Inst. of Information and Communications Technology, Tokyo, Japan
Secret Sharing Scheme Using Natural Language Text
Takizawa, Osamu; Yamamura, Akihiro; Makino, Kyoko; Journal of the National Institute of Information and Communications
Technology. Special Issue on Information Security, Volume 52, Nos. 1/2; March/June 2005, pp. 173-183; In English; See also
20060002073; Copyright; Avail.: Other Sources
Modifying the idea of the visual cryptography, we propose a method of sharing a secret key using natural language tests.
Our target here is restricted to Japanese tests. Each participant obtains a share, which is a Japanese test in our scheme. When
a certain number of participants retrieve the secret key, they supply their shares and pile up these natural language tests. The
sequence of the first, second (and so on) letters occurred in the pile shows the secret text. The order of the pile is significant,
and changing the order may yield the distinct secret text. It is easy to pile the shared natural language texts by computer
operation. Human eyes can recognize the secret text from the piled texts. However, we aim to construct a natural language
text secret sharing scheme employing a morphological analyzer because a meaningless phrase is a chain of morphemes
consisting of one word with a high probability. We can make a shared natural text look like a natural text without any secret
meaning by synthesizing using a text database.
Author
Cryptography; Natural Language (Computers); Algorithms; Texts
20060002089 National Inst. of Information and Communications Technology, Tokyo, Japan
A Generalized Harley Algorithm for Genus Two Hyperelliptic Curves
Sugizaki, Hiroki; Kazuto, Matsuo; Chao, Jinhun; Tsujii, Shigeo; Journal of the National Institute of Information and
Communications Technology. Special Issue on Information Security, Volume 52, Nos. 1/2; March/June 2005, pp. 111-117; In
English; See also 20060002073; Copyright; Avail.: Other Sources
A fast addition algorithm for divisor classes of genus two hyperelliptic curves over finite fields of odd characteristics was
proposed by Harley in 2000 and a lot of improvements of the algorithm has been proposed, besides extensions of the algorithm
for the curves over finite fields of characteristic two have been proposed by the authors and Lange independently. However,
any Harley algorithm over arbitrary characteristic firlds have not been known until now. This paper shows a generalization
of the Harley algorithm to genus two hyper elliptic curves over finite fields of arbitrary characteristics. The proposed algorithm
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