Introduction to Part II

Data to be accessed via communication networks or transmitted over public networks must be protected against unauthorized access, misuse, and modification. Security protection requires three mechanisms: enablement, access control, and trust management. Enablement implies that a cohesive security policy has been implemented and that an infrastructure to support the verification of conformance with the policy is deployed. Perimeter control determines the points of control, the objects of control and the nature of control to provide access control and perform verification and authorization. Trust management allows the specification of security policies relevant to trust and credentials. It ascertains whether a given set of credentials conforms to the relevant policy, delegates trust to third parties under relevant conditions, and manages dynamically, if needed, the level of trust assigned to individuals and resources in order to provide authorization.

Public key infrastructures (PKIs) represent an important tool to be used in enablement, while biometric-based infrastructures are gaining an important role in providing robust access control. Biometrics are automated methods of recognizing a person based on a physiological or behavioral characteristic. Biometric-based solutions are able to provide for confidential financial transactions and personal data privacy. The need for biometrics can be found in electronic governments, in the military, and in commercial applications. In addition, trust management systems start to be used in a large set of environments such as electronic payment and healthcare management, where transactions and accesses are highly sensitive.