trust
1. In cryptology and cryptosystems, that characteristic allowing one entity to assume that a second entity will behave exactly as the first entity expects.
Note: Trust may apply only for some specific function. The critical role of trust in the authentication framework is to describe the relationship between an authenticating entity and a certification authority; an authenticating entity must be certain that it can trust the certification authority to create only valid and reliable certificates. [After X.509]
2. reliance upon Security Measures to uphold the Security policy [CESG].
Note: The term is not synonymous with “trustworthyâ. The trustworthiness of trusted items may be established (e. g. by evaluation) at a later stage.
3. A relationship between two elements, a set of activities and a security policy in which element X trusts element Y if and only if X has confidence that Y will behave in a well defined way (with respect to the activities) that does not violate the given security policy [10181-1].
4. Confidence, that may be based on assurances which are outside the scope of this Report, that an entity to which trust is applied, will perform in a way that will not prejudice the security of the user of the system of which that entity is a part. trust is always restricted to specific functions or ways of behavior (e.g., “trusted to connect A to B properly”). Trust is meaningful only in the context of a security policy: an entity may be trusted in the context of one policy but untrusted in the context of another policy[ECMATR46].