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数字签名通常作为不可反驳的密码学证据用于解决电子交易中的纷争,但是其可信的时间戳和证书撤销服务在实际使用中代价很高。免撤销公钥框架作为一种新的PKI使得终端用户可以控制他自己的公钥证书的有效性,使验证证书不需要折回到CA去获取证书撤销信息.从而降低其使用代价。 相似文献
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Ricardo Garcia-Padron Dan Loyd Stefan Sjökvist 《Subsurface Sensing Technologies and Applications》2002,3(2):125-150
One promising method of locating buried objects, such as land mines, is to use optical systems for detecting contrasts in surface temperature. With enhanced knowledge about the interacting physical processes behind these temperature contrasts, it is possible to improve detection precision. In such a context, moisture movement in the soil and moisture evaporation from the surface have been found to be of particular interest. This study was based on indoor experiments on wet and dry sand exposed to radiation from a solar panel. Simulations of heat and moisture transfer conducted with a one-dimensional model are also presented for the experiments. The calculations were successful in accurately predicting surface temperatures for both wet and dry sand, making it possible to predict surface temperatures under different conditions. These findings will contribute to increasing the probability of successful detection of buried objects under real conditions using optical methods. 相似文献
14.
一个安全有效的身份鉴别协议与对应的数字签名方案 总被引:3,自引:0,他引:3
本文利用二元一次不定方程和Schnorr身份鉴别协议,构造出一个新的身份鉴别协议,该协议在RSA问题和离散对数问题是难解的假设下是安全的,同时给出了所对应的数字签名方案。 相似文献
15.
本文在广义ElGamal型签名方案上建立了许多口令鉴别方案,并且提出了文[1]的三个改进方案。利用这些方案,计算机系统不仅能监测和控制口令的使用,而且可以抗击许多对口令的伪造攻击。 相似文献
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In this article we propose efficient scan path and BIST schemes for RAMs. Tools for automatic generation of these schemes have been implemented. They reduce the design effort and thus allow the designer to select the more appropriate scheme with respect to various constraints. 相似文献
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Signature analyzers are very efficient output response compactors for BIST design. The only limitation of signature analysis is the fault coverage reduction (aliasing) due to the information loss inherent to any data compaction. In this article, in order to increase the effectiveness of ROM BIST, we take advantage from the simplicity of the error patterns generated by ROMs and we show that aliasing free signature analysis can be achieved in ROM BIST.This work was performed when the author was on leave from Minsk Radio Engineering Institute, Computer Department, Belorus. 相似文献
18.
Pseudo-random testing techniques for mixed-signal circuits offer several advantages compared to explicit time-domain and frequency-domain test methods, especially in a BIST structure. To fully exploit these advantages a suitable choice of the pseudo-random input parameters should be done and an investigation on the accuracy of the circuit response samples needed to reduce the risk of misclassification should be carried out. Here these issues have been addressed for a testing scheme based on the estimation of the impulse response of the device under test (DUT) by means of input-output cross-correlation. Moreover, new acceptance criteria for the DUT are suggested which solve some ambiguity problems arising if the classification of the DUT as good or bad is based on a few samples of the cross-correlation function. Examples of application of the proposed techniques to real cases are also shown in order to assess the impact of the measurement system inaccuracies on the reliability of the test. 相似文献
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两个基于身份的数字签名方案的安全性改进 总被引:2,自引:0,他引:2
分析了文献[1]提出的两个基于用户身份的数字签名方案,发现其一般签名方案存在安全性缺陷,在此基础上建立了多重签名方案,但此方案也是不安全的。本文给出了改进的签名和多重签名方案。 相似文献