For each application, which of confidentiality, integrity, and authenticity are required: a digital public archive, Pay-TV data transmission, and an electronic signature?

Question

Accepted Answer

A public archive needs authenticity/integrity. Pay-TV needs confidentiality and integrity. Electronic signatures need authenticity/integrity (no confidentiality).

Application
Confidentiality
Data Authenticity / Integrity

Digital public archive
No — it's public
Yes — must prove documents haven't been tampered with

Pay-TV broadcast
Yes — only paying subscribers should see content
Yes — ensure broadcast data isn't manipulated

Electronic signature
No — the signed document may be public
Yes — must prove who signed it and that it hasn't changed

Key insight: Not every application needs confidentiality! Many real-world systems primarily need authenticity and integrity rather than secrecy. It is widely expected that the proportion of cryptographic user authentication applications will increase significantly over time.

Application	Confidentiality	Data Authenticity / Integrity
Digital public archive	No — it's public	Yes — must prove documents haven't been tampered with
Pay-TV broadcast	Yes — only paying subscribers should see content	Yes — ensure broadcast data isn't manipulated
Electronic signature	No — the signed document may be public	Yes — must prove who signed it and that it hasn't changed