The process of proving identity, authentication services ensure the authenticity of an entity during communication and/or transfer of data.
Access control provides protection against the unauthorized use of system resources that may be accessible. This service
relates to what resources a user or service may access on the system or network.
Data confidentiality services protect data from unauthorized disclosure and passive threats.
Data integrity services protect against active threats by verifying or maintaining the consistency of information.
Repudiation is defined as the denial by one of the entities involved in a communication of having participated in all or part of the communication. Non-repudiation services provide for proof of origin and/or proof of delivery.