Analyze the performance of the existing traitor tracing schemes , design and develop a traitor tracing scheme , with the charateristics of asymmetry , non - repudiation , full frameproof and anti - linear - attack 分析了现有叛逆者追踪方案的各方面性能，设计改进了一种叛逆者追踪方案，该方案具有非对称性、直接不可否认性、防诬陷性及可抵抗线性攻击的特点。
6 a secure web transaction scheme based on mobile agent is proposed . compared with other existing scheme , our scheme has many security properties , such as secrecy , anonymity , effectivity and non - reputation 6设计了一个应用移动代理技术实现的安全web交易方案，同现有的同类方案相比，该方案同时具有高效性、保密性、匿名性、不可否认性等多项安全性能。
In order to ensure the information security , the users can encryption and signature the transmitting data information by using the data certificate , which is issued by the certificate authoware Pki技术采用证书管理公钥，通过ca认证中心发放的数字证书，对要传输的数字信息进行加密和签名，保证信息传输的机密性、真实性、完整性和不可否认性，从而保证信息的安全。
With the development of the communication technology and the internet , information security becomes the most important for its secretive , unanimous and undeniable in storage , exchange and usage 随着通讯技术和网络的发展，信息在存储、交换、使用中的保密性、一致性和不可否认性，越来越成为普遍关注的重大问题，而数据加密技术是实现数据保密防范有效而可行的办法。
The general rule is to encrypt and sign the digital information to be transmitted using digital certificates based on pki , therefore to guarantee the confidentiality , authenticity , integrality and non - repudiation in data transmission 目前,通用的办法是采用建立在pki基础之上的数字证书,通过把要传输的数字信息进行加密和签名,保证信息传输的机密性、真实性、完整性和不可否认性,从而保证信息的安全传输。
Finally , an authentication system is constructed based on digital certificate and cryptography technology , and it can provide a better authentication than the non - cryptographic one which are currently used , and guarantees the confidentiality , integrity , non - repudiation of the information 最后，使用数字证书，运用对称和非对称密码体制等密码技术建立起一套严密的身份认证系统，实现信息传输中的身份认证、机密性、完整性和不可否认性。
Pki ( public key infrastructures ) , which is based on cryptography and provide authentication , confidentiality , integrity and non - repudiation , turns into the source of authentication and authorization in internet . pki records people ' s identities and privileges into public key certificate Pki ( publickeyinfrastructures公钥基础设施)以密码学为理论基础，提供身份鉴别、机密性、完整性和不可否认性服务，成为网络应用中信任和授权的源泉。
It provides the email users security services such as confidentiality , integrity , identification and non - reputation by the combination of providing encryption , decryption , digital signature , verification to the email and key management and web trust 它为电子邮件的正文及附件提供了加密、解密、签名、验证等功能，结合pgp的密钥证书管理功能和网状信任模型，为电子邮件用户提供邮件内容的保密性、完整性、发送方和接收方身份认证以及不可否认性等安全服务。
It provides the email users security services such as confidentiality , integrity , identification and non - reputation by the combination of providing encryption , decryption , digital signature , verification to the email and key management and web trust 它为电子邮件的正文及附件提供了加密、解密、签名、验证等功能，结合pgp的密钥证书管理功能和网状信任模型，为电子邮件用户提供邮件内容的保密性、完整性、发送方和接收方身份认证以及不可否认性等安全服务。
