This book constitutes the refereed proceedings of the 5th European Public Key Infrastructure Workshop: Theory and Practice, EuroPKI 2008, held in Trondheim, Norway, in June 2008. The 15 revised full papers presented together with 1 invited paper were carefully reviewed and selected from 37 submissions. Ranging from theoretical and foundational topics to applications and regulatory issues in various contexts, the papers focus on all research and practice aspects of PKI and show ways how to construct effective, practical, secure and low cost means for assuring authenticity and validity of public keys used in large-scale networked services.

Invited Talk.- New PKI Protocols Using Tamper Resistant Hardware.- Certificates.- Validation Algorithms for a Secure Internet Routing PKI.- Instant Revocation.- Optimized Certificates - A New Proposal for Efficient Electronic Document Signature Validation.- Authentication.- An Efficient and Provable Secure Identity-Based Identification Scheme in the Standard Model.- Trust-Rated Authentication for Domain-Structured Distributed Systems.- Levels of Assurance and Reauthentication in Federated Environments.- Practice.- Current Status of Japanese Government PKI Systems.- A Privacy-Preserving eHealth Protocol Compliant with the Belgian Healthcare System.- Signatures.- Fast Point Decompression for Standard Elliptic Curves.- An Efficient Strong Key-Insulated Signature Scheme and Its Application.- Efficient Generic Forward-Secure Signatures and Proxy Signatures.- Analysis.- Fault Attacks on Public Key Elements: Application to DLP-Based Schemes.- Weaknesses in BankID, a PKI-Substitute Deployed by Norwegian Banks.- Networks.- An Open Mobile Identity Tool: An Architecture for Mobile Identity Management.- PEACHES and Peers.