中文摘要：

针对网络内容生命周期隐私保护问题,结合多级安全、基于身份的加密（Identity-Based Encryption,IBE）和分布式Hash表（Distributed Hash Table,DHT）网络,提出了一种面向网络内容隐私的基于身份加密的安全自毁方案.为了实现密文安全,将网络内容划分为不同安全等级的隐私内容块,经对称密钥加密转变为原始密文;借助耦合和提取方法,将原始密文变换为耦合密文并进一步分解成提取密文和封装密文,然后将封装密文保存到存储服务提供商.为进一步保护网络内容过期后的隐私安全,对称密钥经IBE加密后的密文与提取密文一起经拉格朗日多项式处理生成混合密文分量并分发到DHT网络中.当超过生存期限,DHT网络节点将自动丢弃所存密文分量,从而使对称密钥和原始密文不可恢复,实现网络内容安全自毁.综合分析表明,与已有方案相比,该方案满足设计目标,不仅能抵抗传统密码分析攻击和蛮力攻击,还能抵抗DHT网络的跳跃和嗅探等Sybil攻击.

英文摘要：

With the rapid emerging of novelty Web services and cloud services,privacy information and documents of users become increasingly easy to be exposed in the Internet.To tackle the issue of lifecycle security of the privacy information and documents in the Internet,in this paper,we propose the idea of combining the three security methods of multilevel security,identity-based encryption （IBE）,and distributed hash table （DHT） network.And we further propose an IBE-based secure self-destruction （ISS） scheme to protect the confidentiality and privacy of the Internet content by self-destruction after a predefined time.In our proposed ISS security scheme,the Internet content is first partitioned into many segments with diverse security levels,and each segment is encrypted with a symmetric key to obtain primitive ciphertext.By applying the methods of association and extraction,the primitive ciphertext is turned to associated ciphertext,which is then divided into extracted ciphertext and encapsulated ciphertext.The latter is encapsulated into the Internet content self-destructing object （CDO）,which is stored into the storage services provider.Furthermore,to protect the privacy security when the CDO expired,the symmetric key is encrypted using the IBE algorithm based on the identity of the authorized user.The combination of this key＇s ciphertext and the extracted ciphertext,by means of Lagrange polynomial processing,generates mixture ciphertext shares.Then those shares are distributed into nodes within the DHT network and will be automatically discarded over the deadline when the primitive ciphertext and the symmtric key are unrecoverable.Consequently,the ISS scheme achieves the aim of secure self-destruction.Comprehensive analysis shows that the ISS scheme is able to satisfy all the design demands and is more secure than existing schemes.The ISS scheme can resist against not only the traditional cryptanalysis and brute-force attack,but also the Sybil attack （e.g.,hopping attack and sniffer attack） from