Abstract:
The invention relates to a method of carrying out a cryptographic task using a public key. The inventive method can be used to reduce the computation load of the verifier, consisting of entity B, in a secure electronic transaction incorporating a message authentication, identification or electronic signature mechanism. Said method consists in delegating one part of the calculations to a not necessarily-trustworthy external entity C without diminishing the verifier's level of conviction regarding the verification step. More specifically, the method consists in dividing the verification task into at least two steps (6, 15) and (8, 17), such that at least step 6, 15 can be executed by external entity C. In particular, the method can be applied to the RSA (Rivest, Shamir, Adleman) electronic signature system and to certain message authentication protocols based on the discrete logarithm.
Abstract:
PROBLEM TO BE SOLVED: To surely distribute responsibilities among a plurality of management servers in order to prevent an illegal attempt from hampering the confidentiality and the integrity of voting, in a method and a system for enabling electronic voting over a high-security network. SOLUTION: An authentication certificate CA is calculated by a management server SA and transmitted to a voting terminal Te, an electronic voting paper EB and an anonymous reference code AREu selected by a voter Eu are transmitted from the voting terminal to a voting count server SCV, and upon the verification of the anonymous reference by using a true value, electronic voting paper and the electronic voting of the voter are validated, the electronic voting paper is counted according to a surface value of the electronic voting paper, the confirmation of receipt is transmitted from the voting count server to the voting terminal. Eligible voter list documents SDVR signed by authentication certificates are calculated by the voting terminal and transmitted to the management server. The management server closes the voting action of the voter when the signed eligible voter list documents are verified by using a true value. COPYRIGHT: (C)2006,JPO&NCIPI
Abstract:
PROBLEM TO BE SOLVED: To provide a new fair blind signature process. SOLUTION: In the fair blind signature process, a user converses with a signer to complete a 7-tuple (A, e, s, t, x u , x, m) so that A e =a 0 a x 1 a m 2 a xu 3 a t 4 a s 5 (mod n) may be satisfied. Here, a 0 , a 1 , a 2 , a 3 , a 4 , a 5 , and n are elements of public keys (PUBK S ) of the signer. During a signature issuing phase, the user (U) supplies a data element (a 1 x ) enciphered according to already-known key (f) by a reliable organization (TA) to the signer (S), and this data element (a 1 x ) is indicated while a signed message is transmitted. Similarly, the signed message is transmitted in relation to second enciphered data comprising a second data element a xu 3 enciphered according to the already-known key (f) by the reliable organization (TA), and this second data element a xu 3 is indicated to the signer during the signature issuing phase. COPYRIGHT: (C)2005,JPO&NCIPI
Abstract:
データ交換ネットワーク(2)に接続された複数の端末に同報通信システムによって送信されるスクランブルをかけられたディジタル・データを解読するための個々の解読キーを配分するための方法に関するものであり、同報通信システムは、前記個々のキーを提供するよう設計されたポータル(14)と、少なくとも1つのスクランブリング・プラットフォーム(16)と、スクランブルをかけられたデータを同報通信するための少なくとも1つのサーバ(6)とを備えている。 当該方法は、各々が個々のキーKiの有効性の周期を定義する一連の符号化周期CP i に、送信されるデータのスクランブル周期を分割する段階と、ポータル(14)に端末(4)が接続されるごとに、符号化周期CP i に対応する少なくとも1つのキー及び符号化周期CP i+1 に対応する少なくとも1つのキーを備えた個々のキーの組、並びに継続されるアクセスが認可される場合に、後続の符号化周期に少なくとも対応する解読キーの組を収集するように後続の接続の日付けを該端末(4)に供給する段階とを含む。