串流密文Grain 家族之研究

The study of Stream Cipher Grain Family

石書銘(Shu-Ming Shih)

指導教授 ： 楊吳泉

義守大學/電機資訊學院/資訊工程學系/碩士(2017年)

摘要

Grain串流加密家族是屬於輕量級的串流加密，能在有限的硬體環境中實現，它是歐洲 eSTREAM 最終入選3個硬體面向實現的串流加密演算法之一。主要設計理念是基於兩個移位暫存器和一個非線性輸出函數組成，因此可以透過增加額外的硬體，提升執行速度。
　　本論文針對其兩個版本Grain 和Grain-128加以探討，並透過NIST SP 800-22a亂數統計測試驗證其串流金鑰的隨機性。
　　Grain 除了較無法抵抗窮舉攻擊之外，在亂數測試標準中有未通過的現象，這也表示他的隨機性較有疑慮，Grain-128 則通過所有測試，證明其安全性也相對較高。

關鍵字

串流加密 ； 亂數

並列摘要

A stream cipher family, Grain, is a lightweight stream cipher. It can designs in very limited hardware environments. That is one of the portfolio candidates in the hardware based category of eSTREAM. The main design concept is based on two shift registers and a non-linear output function, that also have the additional feature that the speed can be easily increased at the expense of extra hardware. In this paper, two versions of Grain and Grain-128 are discussed, and the randomness of the keystream is verified by NIST SP 800-22a random number test. Grain have weekness about exhaustive key search, and it could not passed all of the test, this also means that its randomness has doubts. Grain-128 through all tests, that its security is relatively high.

並列關鍵字

eSTREAM ； Grain ； stream cipher ； random number

參考文獻

[3] Benjamin (Bill) Planche, “andom Number Generators, available on http://aldream.github.io/presentations/.

[1] M. Hell, T. Johansson, A. Maximov, and W. Meier, “A stream cipher proposal: Grain-128,” 2006 IEEE International Symposium Information Theory (ISIT2006), pp. 1614-1618, 2006.

[7] I. Dinur and A. Shamir “Breaking Grain-128 with dynamic cube attacks,” 2011 International Workshop on Fast Software Encryption (FSE 2011), pp.167-187, 2011.

[2] Norul Hidayah Lot, Ahmad Zawawi, Kamaruzzaman Seman, Nurzi Juana Mohd Zaizi, “A New Proposed Design of a Stream Cipher Algorithm: Modified Grain-128,” International Journal of Computer and Information Technology, Vol.03, Issue 05, September 2014.

[4] A. Rukhin, J. Soto, J. Nechvatal, M. Smid, E. Barker, S. Leigh, M. Levenson, M. Vangel, D. Banks, A. Heckert, J. Dray, and S.Vo, A Statistical Test Suite for Random and Pseudorandom Number Generators for Cryptographic Applications, NIST Special Publication 800-22 Revision 1a, April 2010