What is NOT one of the four security goals of Cryptography?

The correct answer is availability because it is not traditionally considered one of the primary security goals of cryptography. The four main security goals of cryptography are confidentiality, integrity, authenticity (which can encompass non-repudiation), and sometimes specifically non-repudiation is mentioned as a critical component of security protocols.

Confidentiality ensures that information remains private and is accessible only to those authorized to view it. Integrity guarantees that the data has not been altered or tampered with in transit and remains in its original state when received. Non-repudiation prevents an entity from denying their actions, ensuring accountability in communications.

Availability, while crucial in the broader context of information security and system design, focuses on ensuring that authorized users have access to information and resources when needed. It is not a goal specifically tied to the functions or techniques used in cryptography, which are more focused on the protection of the information itself rather than the operational uptime or accessibility of that information.