无证书条件代理重加密的研究

Certificateless conditional proxy re-encryption (CPRE) is an interesting cryptographic primitive with good application prospects. On the one hand it can control the transformation right of the proxy at a fine-grained level, and on the other hand it does not suffer from neither the key-escrow problem nor the complicated certificate management problem. Nowadays, the study of certificateless CPRE is only in its infancy, and there are still a lot of research problems needed to be resolved. In view of this, in this project we shall study on the following key problems for certificateless CPRE: (i) study on how to formalize the strict security models for certificateless CPRE and its variants; (ii) study on the generic method of constructing certificateless CPRE schemes secure against chosen-ciphertext attacks (CCA), and propose a CCA secure certificateless CPRE in the standard model without pairings; (iii) study on the problem of key-exposure protection for certificateless CPRE, and design forward secure certificateless CPRE, parallel key-insulated certificateless CPRE and intrusion resilient certificateless CPRE schemes; (iv) study on the problem of privacy preserving for certificateless CPRE, and propose anonymous certificateless CPRE and anonymous certificateless threshold CPRE schemes. The research fruits of this project can enrich the theory of certificateless CPRE, and will be also conducive to the wider application of certificateless CPRE.

无证书条件代理重加密是一种具有良好应用前景的密码体制，它既能有效地控制代理者转换密文的权限，又能避免密钥托管和证书管理的问题。目前学界关于无证书条件代理重加密的研究尚处于起步阶段，还有大量的问题有待解决。为此，本项目将针对无证书条件代理重加密的如下重点问题展开研究：（i）研究如何为无证书条件代理重加密及其变体定义严格的安全模型；（ii）研究选择密文安全无证书条件代理重加密的通用构造方法，设计标准模型下不使用双线性配对的选择密文安全无证书条件代理重加密方案；（iii）研究无证书条件代理重加密的密钥泄漏防护问题，分别设计前向安全、并行密钥隔离和入侵回弹的无证书条件代理重加密方案；（iv）研究无证书条件代理重加密的隐私保护问题，设计匿名无证书条件代理重加密和匿名无证书门限条件代理重加密方案。本项目的研究成果将能丰富无证书条件代理重加密的理论，并为无证书条件代理重加密的应用打下基础。

无证书条件代理重加密是一种具有良好应用前景的密码体制，它既能有效地控制代理者转换密文的权限，又能避免密钥托管和证书管理的问题。目前学界关于无证书条件代理重加密的研究尚处于起步阶段，还有大量的问题有待解决。针对这一研究现状，本项目对无证书条件代理重加密的以下关键问题展开了研究：（1）研究如何为无证书条件代理重加密及其变体定义严格的安全模型；（2）研究选择密文安全无证书条件代理重加密的通用构造方法，设计标准模型下不使用双线性配对的选择密文安全无证书条件代理重加密方案；（3）研究无证书条件代理重加密的密钥泄漏防护问题，分别设计前向安全、并行密钥隔离和入侵回弹的无证书条件代理重加密方案；（4）研究无证书条件代理重加密的隐私保护问题，设计匿名无证书条件代理重加密和匿名无证书门限条件代理重加密方案。