翻訳と辞書 Words near each other ・ XTG Extreme Game ・ XTI ・ XTM ・ XTM (band) ・ XTM (TV channel) ・ XTM International ・ XTM-CAT ・ XTNCT ・ XTND ・ XTO Energy ・ Xtol ・ Xtopia ・ Xtort ・ XTP ・ XTP3-transactivated gene A protein ・ XTR ・ Xtra (automobile) ・ Xtra (ISP) ・ Xtra Airways ・ Xtra AM ・ Xtra Bass ・ Xtra Heat ・ XTRA Lease ・ Xtra Mile Recordings ・ Xtra Ottawa ・ Xtra Vancouver ・ Xtra! ・ Xtra-Acme USA ・ Xtra-vision ・ Xtrac Limited Dictionary Lists mini英和辞書 mini和英辞書 Webster 1913 Latin-English FOLDOC Wikipedia English ウィキペディア

翻訳と辞書　辞書検索 [ 開発暫定版 ] スポンサード リンク XTR ： ウィキペディア英語版 XTR In cryptography, XTR is an algorithm for public-key encryption. XTR stands for ‘ECSTR’, which is an abbreviation for Efficient and Compact Subgroup Trace Representation. It is a method to represent elements of a subgroup of a multiplicative group of a finite field. To do so, it uses the trace over $GF(p^2)$ to represent elements of a subgroup of $GF(p^6)^$ *. From a security point of view, XTR relies on the difficulty of solving Discrete Logarithm related problems in the full multiplicative group of a finite field. Unlike many cryptographic protocols that are based on the generator of the full multiplicative group of a finite field, XTR uses the generator $g$ of a relatively small subgroup of some prime order $q$ of a subgroup of $GF(p^6)^$ *. With the right choice of $q$, computing Discrete Logarithms in the group, generated by $g$, is, in general, as hard as it is in $GF(p^6)^$ * and thus cryptographic applications of XTR use $GF(p^2)$ arithmetics while achieving full $GF(p^6)$ security leading to substantial savings both in communication and computational overhead without compromising security. Some other advantages of XTR are its fast key generation, small key sizes and speed. == Fundamentals of XTR == XTR uses a subgroup, commonly referred to as ''XTR subgroup'' or just ''XTR group'', of a subgroup called ''XTR supergroup'', of the multiplicative group of a finite field $GF(p^6)$ with $p^6$ elements. The XTR supergroup is of order $p^2-p+1$, where ''p'' is a prime such that a sufficiently large prime ''q'' divides $p^2-p+1$. The XTR subgroup has now order ''q'' and is, as a subgroup of $GF(p^6)^$ *, a cyclic group $\backslash langle\; g\backslash rangle$ with generator ''g''. The following three paragraphs will describe how elements of the XTR supergroup can be represented using an element of $GF(p^2)$ instead of an element of $GF(p^6)$ and how arithmetic operations take place in $GF(p^2)$ instead of in $GF(p^6)$. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「XTR」の詳細全文を読む スポンサード リンク 翻訳と辞書 : 翻訳のためのインターネットリソース Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.