This book investigates the security and trust issues in mobile services environment and develops solutions based on federated and parameter based identification, authentication and authorization mechanisms. The mobile services are provided by online service providers and identification, authentication, authorization and service access are the main stages of the security framework for service provisioning at the mobile device. Trust negotiation and trust destruction between the mobile users and service providers are required if the authentication credentials are not shared between the two parties for the service provision. The security protection for data in mobile devices is equally important as security on data transmission in communication channels. The book explores three types of mobile services to mobile handsets such as consumer services, anonymous access services and trust delegation services. The authors have identified unique identity parameters at the mobile device and these identities are used to generate a unique identity for the mobile subscriber. This unique identity is used for the authentication mechanisms at the service provider.