Choose the security property

Cryptography solves specific problems. Start by naming the property you need.

Confidentiality hides content. Integrity detects change. Authenticity helps prove who created or approved a message. Some designs need several properties together, and the surrounding system still needs authorization and key management.

A payroll file is encrypted before upload, but nobody verifies who created it. Its contents stay private while an attacker replaces it with different encrypted bytes.

Confidentiality, integrity, and authenticity answer different questions. Availability and authorization sit outside the cryptographic primitive, so name those needs separately.

Write the required properties for a private note, software installer, session cookie, and payroll upload. For each answer, name the attacker and the evidence that the control produces. Then change one case so confidentiality is unnecessary but authenticity remains essential, and explain the different choice.