Which classic element of computer security is generally not required for an encryption scheme?

Which classic element of computer security is generally not required for an encryption scheme?

• A. Confidentiality
• B. Integrity
• C. Availability
• D. Authentication

Answer: (C)

Encryption is designed to keep data secret, so confidentiality is its primary goal. In practice, a strong scheme often also protects against tampering by providing integrity, using authenticated encryption or a MAC. Authentication of who is communicating isn’t an inherent part of the encryption primitive itself; it’s usually handled by the surrounding protocol and key management. Availability, however, concerns system uptime and access to resources, which encryption does not address. An encryption scheme doesn’t guarantee that a system will be available, so this is not generally a requirement of the encryption itself.

Encryption is designed to keep data secret, so confidentiality is its primary goal. In practice, a strong scheme often also protects against tampering by providing integrity, using authenticated encryption or a MAC. Authentication of who is communicating isn’t an inherent part of the encryption primitive itself; it’s usually handled by the surrounding protocol and key management. Availability, however, concerns system uptime and access to resources, which encryption does not address. An encryption scheme doesn’t guarantee that a system will be available, so this is not generally a requirement of the encryption itself.