可签名的

A comprehensive research has made in the application of elliptic curve based bilinear mapping in the group signature, security of bilinear mapping is established on the GAP group. Because the DDH problem is easy to solve in GAP, this fact results it is very difficult to design a bilinear mapping based group signature scheme which can satisfy anonymity and the tractability.

对基于椭圆曲线的双线性映射在群签名中的应用进行了深入的研究，由于双线性映射的安全性建立在GAP群上，而在GAP群上的DDH问题是容易求解的，这样导致在基于双线性映射的群签名方案设计中很难同时兼顾群签名的匿名性和可跟踪性。

As the extension of restrictive blind signature, partially restrictive blind signature allows some public information to be included in the signature while the anonymity and exposure ability against double signer of receiver are still hold.

部分受限盲签名是受限盲签名的扩展，使用该技术可以在实现接收者的匿名性和重复签名可揭示性的同时，将某些公共消息编码到签名中。

The results show that the KPW scheme is not a nominative signature scheme since the nominator not only can verify and prove the validity of given signatures but also can convert given signatures into universally verifiable signatures, and that the PL scheme is only a self-authentication signature scheme since anyone can verify the validity of given signatures.

摘要该文分别对一个指名签名方案和一个指名代理签名方案进行分析，结果表明：在KPW方案中签名人不仅能验证而且也能向第三方证明签名的有效性，甚至能将签名转化为通常的自认证签名，因此不是指名签名方案；在PL方案中任何人都可验证签名的有效性，它只是一个自认证签名方案。

And then, this dissertation proposed a secret sharing scheme of secure vector space based on quadratic residue.

利用特定条件下计算二次剩余的困难性，恢复秘密时验证各参与者提供的份额的有效性，也=肖清华二杜绝了恶意参与者欺诈的可能性；(2)在秘密共享一多重签名方面，本论文针对数字签名的可跟踪性，以及确认签名是否来自同一个参与者授权子集这两个问题，指出了秘密共享和多重签名各自存在的不足，在此基础上，把两者结合起来，并从门限秘密共享一多重签名、矢量空间秘密共享一多重签名两方面对秘密共享一多重签名技术进行探讨，把 Sunder一Kumar门限秘密共享一多重签名方案推广到更为广泛的矢量空间上，并独立地提出了一个双通道的安全矢量空间秘密共享一多重签名方案。

In order to improve the security, a signature scheme based on two hard problem assumptions is proposed. The security of the scheme is based on the difficulties of simultaneously solving the elliptic curve and quadratic residue. A attacker can't forge the signature of messages even if a attacker can solve theelliptic curve discrete logarithm problems or quadratic residue problem in the scheme.

为了提高签名的安全性，本文对Wang等人提出的签名方案进行改进，提出了一个基于椭圆曲线离散对数问题和二次剩余问题的数字签名方案，并对该方案的安全性进行分析，指出在椭圆曲线离散对数问题或二次剩余问题可解的情况下，攻击者也无法伪造消息的签名。

Aiming at the problem of fair exchange of digital signatures, a scheme of revocable concurrent signatures is proposed.

针对数字签名的公平交换问题，提出了可废除并发签名机制。

The scheme shows that the new scheme is an implementation of secure and efficient confirmer signature.

在证实数字签名方案中，签名的证实和否认功能由一个半可信任的第3方承担，同时证实者具有转化一个证实数字签名为一个普通数字签名的能力。当然，签名者不能参与证实的过程，证实者也不能参与签名的过

The scheme is the improvementof confirmer digital signature. Also it is simpler and doesnt require the participation of the confirmer.

该方案是可证实数字签名的改进，比证实签名简单且不需要第三方的参与。

Electric seal is a method to sign a document and it is a kind of electric signature, though a document has some difference compare to other kind of data like program, data of a database, according the speciality of a electric signature to a document, such as view what we signed , validate the signature in a document directly, how to archives a document which has been signed, how to read a document has been archived, it points out that a document is exactly some data with some format data, a document could be disparted as two parts, data and format data.

电子印章是应用层的数字签名，是电子签章的一种，由于文档签名与其他类型数据如程序，数据库数据等相比有其特殊性，本文针对文档签名的特殊性，如签名的可见与可证实性，文档的归档特性，文档阅读的方便性等进行了分析，指出文档实际上是一种格式化的数据，可以分为数据与格式两个部分，在此基础上提出了对文档进行签名的要求。

First,the number of group members is not fixed in the setup phase and the group public key is unchanged.Second,an entity can join the group at any time and obtain a private signing key without refashioning other group members' private signing key.Third,the identity of the group signature can be open by the authority and the procedure of the tracing can be check by anybody.

该方案有下列特点：在建群阶段不需要确定成员的数目并且群公钥固定不变；任何时候实体都能通过群权威加入到群中获得签名私钥并且无需更新其他成员的签名私钥；能通过群权威揭示签名人的身份并且这一过程是可验证的。

As she looked at Warrington's manly face, and dark, melancholy eyes, she had settled in her mind that he must have been the victim of an unhappy attachment.

每逢看到沃林顿那刚毅的脸，那乌黑、忧郁的眼睛，她便会相信，他一定作过不幸的爱情的受害者。

Maybe they'll disappear into a pothole.

也许他们将在壶穴里消失