签名

The DH protocol, ElGamal encryption and ElGamal signature scheme, DSA are extended to Hypereliptic curves, and a new message recovery signature scheme based on Hyperelliptic curves is presented. And it is proved that this new message recovery signature scheme is not strong equivalent to HC-ElGamal signature scheme.

将DH协议、ElGamal加密体制、ElGamal签名和DSA推广到了HC上，提出了一个基于超椭圆曲线的消息恢复签名方案，并证明了这个消息恢复签名方案与HC-ElGamal签名方案不是强等价的。

Today, all the known proxy digital signature schemes has the same problem that can't provide the overall, complete, reliable control ability on the stretch of proxy digital signature power. In this paper, we advances a new proxy digital signature scheme based on hyperelliptic curve discrete algorithmic problems which is called as Xiao's Hyperelliptic Curve Limited Proxy Signature.

本文针对目前的各种代理签名方案所存在的无法实现对代理签名者的代理签名权力进行全面、完整、可靠地控制的问题，提出了一种具有限制代理签名者行使代理签名权力的基于超椭圆曲线离散对数问题的新型可控代理签名方案XHCLPS，同时对这一方案的复杂性和安全性进行了分析。

Besides, the proposed group signature scheme was long in length and the signatures of the same signer are linkable.

除此之外，所构造的群签名方案本身也存在签名长度过长、同一签名成员的签名存在关联性的缺陷。

Finally this thesis analyses the efficient revocable group signature scheme with forward security proposed by Chen Shaozhen and Li Daxirig. An adversary can personate a legal group member by forge a group membership certificate, and then can forge group signatures that can be verified by a verifier. And the group manager can also forge group signatures that can be verified by a verifier. So the scheme is insecure. Meanwhile, there are redundancy steps in the scheme, thus the efficiency is low.

接着，对陈少真和李大兴提出的一种有效取消的前向安全群签名方案进行了密码学分析，一方面，攻击者可以通过伪造群成员证书来伪造能够通过验证的群签名；同时，群管理员也可以伪造一个可以通过验证的群签名，因此，该群签名体制是不安全的；另一方面，该体制存在冗余数据。

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。

Because the special points can be regarded as features,and used as references in segmentation and alignment.This paper proposed an approach based on approximate string match to match the sequence of special points.

实现签名认证的方法大体上可以分为两类，第一类是从签名样本中提取一些全局参数作为特征，第二类则把签名样本的整个信号序列，如坐标序列ux，uy、压力序列up、速度序列uv等看作是时间的函数，把这些函数作为签名的特征[4~6]。

Digital signatures provide solutions for problems in the Internet such as identity authentication, data integrity and nonrepudiation. So digital signature technique has been studied widely, and various digital signature schemes suit for special cases have been proposed.

数字签名为网络环境下的身份认证题目、数据完全性题目、不可否认性等题目提供了可行的解决计划，因此数字签名得到普遍研讨，多种适用于特殊情形的数字签名被提出，群签名就是其中很主要的一种。

In this scheme, by means of the sequence secret sharing scheme, the verification participators can divide the signature verifier from the chain grantors, the signature verifier cannot verify the validity of the signature until he is authorized by all chain grantors in turn, and any chain grantor(even all chain grantors are collusive)cannot verify the validity of the signature.

利用有序秘密分享方法将验证参与者分为签名验证者和链式验证授权者，签名验证者只有在经过链式验证授权组中每一个成员的依次授权时，才可以验证签名的有效性，而且链式验证授权组中的任何成员都不能验证签名的有效性。

Universal designated multi-verifiers signature scheme allowed a signature holder to designate a set of signature verifiers, in such a way that only designated verifiers could verify the efficiency of the signature.

广义指定多个验证者签名体制允许签名的持有者指定多个签名的验证者，只有被指定的验证者可以验证签名的有效性。

The sizes of the proxy signatures in proxy multi - signature scheme is independent of the number of original signers.

在代理多签名方案中，代理签名的长度均独立于原始签名人的个数，其验证也与一般的代理签名类似。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。