Which foundational requirement includes strength of public key authentication?

The foundational requirement that includes the strength of public key authentication is Identification and Authentication Control (IAC). This requirement focuses on ensuring that entities (users, systems, etc.) are properly identified and authenticated before they are allowed access to systems or data. Public key authentication is an important aspect of this process, as it relies on cryptographic methods to verify the identity of users and devices.

Public key infrastructure (PKI) enables secure, scalable authentication through asymmetric cryptography, where a public key can be shared openly while the private key is kept secret. The strength of this method lies in the complexity and security of the keys used, making unauthorized access significantly more difficult.

In contrast, the other foundational requirements do not directly address the strength of authentication methods. Use Control focuses on limiting access based on roles and responsibilities, System Integrity pertains to the accurate functioning of systems and protection against unauthorized changes, and Data Confidentiality emphasizes maintaining the privacy of data through encryption and access controls. Therefore, while all these components are essential for overall cybersecurity, only Identification and Authentication Control specifically addresses the strength and mechanisms of authentication, including public key authentication methods.