LF-PKI: Practical, Secure, and High-Performance Design and Implementation of a Lite Flexible PKI

Sammanfattning

Today’s Web Public Key Infrastructure (PKI) builds on a homogeneous trust model. All Certificate Authorities (CAs) are equally trusted once they are marked as trusted CAs on the client side. As a result, the security of the Web PKI depends on the weakest CA. Trust heterogeneity and flexibility can be introduced in today’s Web PKI to mitigate the problem. Each client could have different levels of trust in each trusted CA, according to the properties of each CA, such as the location, reputation and scale of the CA. As a result, the loss caused by the compromise of a less trusted CA will be relieved. In this work, we study Flexible-PKI (F-PKI), which is an enhancement of Web PKI, and propose Lite Flexible-PKI (LF-PKI) to address the limitations of F-PKI. LF-PKI is designed to securely and efficiently manage domain policies and enable trust heterogeneity on the client side. The domain owner can issue domain policies for their domains, and the client will have a complete view of the domain policies issued for a specific domain. Based on the collection of domain policies from LF-PKI, trust heterogeneity can be achieved on the client side. Each client will choose the domain policies based on the trust levels of the CA. On the basis of the LF-PKI design, a high-performance implementation of LF-PKI was developed, optimized, and analyzed. The optimized implementation can provide the LF-PKI services for worldwide domains on a single server with moderate hardware.