翻訳と辞書 Words near each other ・ Dinn Corporation ・ Dinna Bjørn ・ Dinnebitodon ・ Dinneen ・ Dinner ・ Dinner (disambiguation) ・ Dinidoridae ・ Dinidu Marage ・ Dinie Fitri ・ Dinies Camp ・ Diniktum ・ Dinilysia ・ Dining Bar Akira ・ Dining car ・ Dining club ・ Dining cryptographers problem ・ Dining Downunder ・ Dining in ・ Dining philosophers problem ・ Dining rights ・ Dining room ・ Dining with the Sharks ・ Dininho ・ Dinio ・ Dinis (disambiguation) ・ Dinis (given name) ・ Dinis (surname) ・ Dinis Dias ・ Dinis Gregório de Melo Castro e Mendonça ・ Dinis of Braganza, Count of Lemos 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 Dining cryptographers problem ： ウィキペディア英語版 Dining cryptographers problem In cryptography, the dining cryptographers problem studies how to perform a secure multi-party computation of the boolean-OR function. David Chaum first proposed this problem in 1988, and used it as an illustrative example to show it was possible to send anonymous messages with unconditional sender and recipient untraceability. Anonymous communication networks based on this problem are often referred to as DC-nets. Despite the word ''dining'', the dining cryptographers problem is unrelated to the dining philosophers problem. == Description == Three cryptographers gather around a table for dinner. The waiter informs them that the meal has been paid for by someone, who could be one of the cryptographers or the National Security Agency (NSA). The cryptographers respect each other's right to make an anonymous payment, but want to find out whether the NSA paid. So they decide to execute a two-stage protocol. In the first stage, every two cryptographers establish a shared one-bit secret, say by tossing a coin behind a menu so that only two cryptographers see the outcome in turn for each two cryptographers. Suppose, after the coin tossing, cryptographer A and B share a secret bit $\backslash scriptstyle\; 1$, A and C share $\backslash scriptstyle\; 0$, and B and C share $\backslash scriptstyle\; 1$. In the second stage, each cryptographer publicly announces a bit, which is * if they didn't pay for the meal, the Exclusive OR (XOR) of the two shared bits they hold with their two neighbours * if they did pay for the meal, the opposite of that XOR. Suppose none of the cryptographers paid, then A would announce $\backslash scriptstyle\; 1\; \backslash ,\backslash oplus\backslash ,\; 0\; \backslash ;=\backslash ;\; 1$, B would announce $\backslash scriptstyle\; 1\; \backslash ,\backslash oplus\backslash ,\; 1\; \backslash ;=\backslash ;\; 0$, and C would announce $\backslash scriptstyle\; 0\; \backslash ,\backslash oplus\backslash ,\; 1\; \backslash ;=\backslash ;\; 1$. On the other hand, if A paid, he would announce $\backslash scriptstyle\; \backslash lnot\; \backslash ;=\backslash ;\; 0$. After the second stage is the truth revealing. One simply performs XOR of all the announced bits. If the result is 0, then it implies that none of the cryptographers paid (so NSA must have paid). Otherwise, it would imply one of the cryptographers paid, but their identity remains unknown to the other cryptographers. David Chaum coined the term ''dining cryptographers network'', or DC-net, for this protocol. 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「Dining cryptographers problem」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.