---
abstract: 'Trusted Computing is a security base technology that will perhaps be ubiquitous in a few years in personal computers and mobile devices alike. Despite its neutrality with respect to applications, it has raised some privacy concerns. We show that trusted computing can be applied for service access control in a manner protecting users’ privacy. We construct a ticket system — a concept which is at the heart of Identity Management — relying solely on the capabilities of the trusted platform module and the standards specified by the Trusted Computing Group. Two examples show how it can be used for pseudonymous and protected service access.'
author:
- Nicolai Kuntze
- 'Andreas U. Schmidt'
title: Trusted Ticket Systems and Applications
---

Introduction {#intro}
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In a ticket based authentication and authorisation protocols like Kerberos [@Kerberos] software tokens are used to prove the identity of a single entity. Based on this tokens access to certain systems is restricted to entities producing appropriate tokens. Additionally data embodied in the token can be used to implement also an authorisation control enabling a token based access control scheme beside the mere authentication. These tokens are an electronic analog to physical tickets. They can have 