ITPEC FE Morning October 2019 Question 41

Authenticity — ISO/IEC 27000 defines it as the "property that an entity is what it claims to be".

Authenticity is about genuineness: a user, a device or a message really is the one it claims to be. It is confirmed by authentication, for example a password, a certificate or a digital signature. ISO/IEC 27000 lists it with accountability, non-repudiation and reliability as properties that information security can also involve, beyond confidentiality, integrity and availability.

Answer (b)

Why not others:

• •(a) Accountability — the actions of an entity can be traced back to that entity, which answers for them; it is about who did what, not whether an identity is genuine
• •(c) Nonrepudiation — the ability to prove that a claimed event or action took place and which entity originated it, so it cannot be denied later
• •(d) Reliability — the property of consistent intended behaviour and results

Key rule: Authenticity asks "is it really who or what it claims to be?"; non-repudiation asks "can the act be proved afterwards?"; accountability asks "can the act be traced to its doer?"

Security · AI-written, may contain errors