Beta 1

Title Probalistic public-key confidence valuation model for a peer to peer PKI
Author Cholewinski, Tomasz
Supervisor Jensen, Christian D. (Department of Informatics and Mathematical Modeling, Technical University of Denmark, DTU, DK-2800 Kgs. Lyngby, Denmark)
Institution Technical University of Denmark, DTU, DK-2800 Kgs. Lyngby, Denmark
Thesis level Master's thesis
Year 2004
Abstract Peer to Peer systems are becoming widespread throughout the Internet and pervasive computing systems. Existing PKI infrastructures - both hierarchical and non-hierarchical cannot be directly ported to P2P environments. This is because existing PKIs rely heavily on the presence of CAs, which act as a "trusted third party" in the system. The problem of feasibility of implementation of various functions performed by PKI systems in such an environment is analyzed. The goal of this thesis is to explore the possibility of implementing a Peer to Peer PKI system based on the idea behind the PGP Web of Trust and a probabilistic algorithm to evaluate the con dence in a public-key from a CA, which is described in the paper "Modeling a PKI Infrastructure" by Ueli Maurer [19]. The public-key valuation model makes assumptions about trust in the "trusted third party" explicit, which allows the system to use key-servers that are not completely trusted. This is particularly helpful in a wireless P2P environment targeted by this work. The feasibility of implementation of the probabilistic confidence parameter valuation model is evaluated using a software prototype. The conclusions drawn during the design and implementation phases of the prototype serve as a basis of an overall feasibility evaluation. A problem is identified involving the complexity of calculations of higher level trust paths. Further research paths are outlined, including sensitivity analysis for nding certi cation paths which contribute most to the end-value of the confidence parameter.
Imprint Department of Informatics and Mathematical Modeling, Technical University of Denmark, DTU : DK-2800 Kgs. Lyngby, Denmark
Keywords Peer to Peer; P2P; Public Key Infrastructure; PKI; PGP Web of Trust; Trust; Authenticity; Java
Original PDF imm3254.pdf (1.22 MB)
Admin Creation date: 2006-06-22    Update date: 2012-12-21    Source: dtu    ID: 154739    Original MXD