The contributions of this thesis fall into three areas of certificateless cryptography. The first area is encryption, where we propose new constructions for both identity-based and certificateless cryptography. We construct an n-out-of- n group encryption scheme for identity-based cryptography that does not require any special means to generate the keys of the trusted authorities that are participating. We also introduce a new security definition for chosen ciphertext secure multi-key encryption. We prove that our construction is secure as long as at least one authority is uncompromised, and show that the existing constructions for chosen ciphertext security from identity-based encryption also hold in the group encryption case. We then consider certificateless encryption as the special case of 2-out-of-2 group encryption and give constructions for highly efficient certificateless schemes in the standard model. Among these is the first construction of a lattice-based certificateless encryption scheme. Our next contribution is a highly efficient certificateless key encapsulation mechanism (KEM), that we prove secure in the standard model. We introduce a new way of proving the security of certificateless schemes based that are based on identity-based schemes. We leave the identity-based part of the proof intact, and just extend it to cover the part that is introduced by the certificateless scheme. We show that our construction is more efficient than any instanciation of generic constructions for certificateless key encapsulation in the standard model. The third area where the thesis contributes to the advancement of certificateless cryptography is key agreement. Swanson showed that many certificateless key agreement schemes are insecure if considered in a reasonable security model. We propose the first provably secure certificateless key agreement schemes in the strongest model for certificateless key agreement. We extend Swanson's definition for certificateless key agreement and give more power to the adversary. Our new schemes are secure as long as each party has at least one uncompromised secret. Our first construction is in the random oracle model and gives the adversary slightly more capabilities than our second construction in the standard model. Interestingly, our standard model construction is as efficient as the random oracle model construction.

Jan 1, 20100 citations

Generic Certificateless Encryption Secure Against Malicious-but-Passive KGC Attacks in the Standard Model

Huang Qiong, 王石

尽管有计划最近建议了的无证书的加密的大数字，许多在实际攻击下面他们被发现不可靠，叫的 malicious-but-passive KGC (关键产生中心) 攻击。在这个工作，我们建议无证书的加密的第一通用构造，它能在标准模型对 malicious-but-passive KGC 攻击被证明安全。为了加密任何长度的一条消息，我们在无证书的背景认为 KEM/DEM (关键封装机制 / 数据封装机制) 是框架，并且建议无证书的关键封装机制(CL-KEM ) 的通用构造，在标准模型对 malicious-but-passive KGC 攻击固定。它基于基于身份的 KEM，公钥加密和消息认证代码。我们的构造的高效率由于这些的有效实现位于积木下面，并且比得上 Bentahar et al.s CL-KEMs，它仅仅没有 malicious-but-passive KGC 攻击的考虑在随机的神谕模型下面被证明安全。我们也介绍无证书的基于标签的 KEM (CL-TKEM ) 的观点，它是艾贝等的延期。s 工作到无证书的背景。我们证明有效 CL-TKEM 能被修改我们的 CL-KEM 计划构造。我们也与 CL-TKEM 和在我们的建议安全模型，下面安全的数据封装机制显示出那有效无证书的混合加密能被使用艾贝等构造。的在无证书的背景的转变。

Journal of Computer Science and TechnologyJan 1, 20100 citations