A contractor denies approving a fraudulent wire after their account was used. Which security concept makes repudiation harder by providing reliable evidence of who authorized an action?

Non-repudiation provides assurance that a party cannot credibly deny having performed an action because reliable evidence binds the actor to the event. Strong authentication records, digital signatures, cryptographic transaction signing, and trustworthy authorization logs make it harder for a contractor to claim they never approved a wire when their account was used. The security concept is about evidentiary binding and accountability, not merely encrypting amounts or keeping a portal online.

Choosing availability—keeping the wire portal online during the dispute—addresses uptime, not proof of who authorized the transfer. Choosing confidentiality—encrypting the wire amount from auditors—protects secrecy and can even work against investigation if auditors are improperly denied needed visibility; confidentiality does not establish who approved the payment. Choosing gap analysis—listing missing MFA as a future roadmap item—identifies control shortfalls for remediation planning but is not itself the property that prevents repudiation of a past action.

Exam caveat: non-repudiation is adjacent to AAA accounting and cryptographic signing. SY0-701 may present disputed financial or administrative actions in municipal scenarios; pick the concept that supplies binding evidence, not a CIA goal that happens to appear in the vignette.

Operational check: for city finance wires and contractor portals, require phishing-resistant MFA, retain immutable auth and approval logs, prefer digitally signed or dual-control approvals for high-value transfers, and ensure legal and audit teams can retrieve evidence quickly when someone denies an action.