List and describe three architectural tactics from the 'Withstand Cyber Events' category that can be used to proactively resist attacks.

Three Withstand Cyber Events tactics are validate inputs, authenticate actors, and limit exposure. Validate inputs sanitizes, neutralizes, and validates any externally provided inputs to prevent malformed data or code injection. Authenticate actors verifies that an actor is indeed who it claims to be. Limit exposure minimizes the attack surface by designing the system with the least needed number of entry points.

These tactics proactively resist attacks by addressing common attack vectors at the architectural level. Validate inputs is applied to all externally supplied data, ensuring malformed or malicious content does not enter the system and cannot be used for injection attacks. Authenticate actors forces the system to check the identity of users or external agents, preventing unauthorized actors from being accepted as legitimate. Limit exposure reduces the number and complexity of entry points, so attackers have fewer opportunities and interfaces to exploit. Together, these three examples from the Withstand Cyber Events category illustrate proactive resistance based on input validation, identity verification, and attack surface reduction.