Give an example of two security goals that can directly conflict with each other.

Authentication vs. anonymity, and anonymity vs. non-repudiation — you often can't have both at once.

Some goals pull in opposite directions, so each application must weight them differently:

• Authentication vs. anonymity: paying by bank/credit card requires identifying you — which rules out anonymity. (Cash keeps anonymity but drops the identity link.)
• Anonymity vs. non-repudiation (Verbindlichkeit): legally binding actions require proving a real person's identity — which excludes anonymous, end-to-end participation. You can't be both unidentifiable and held accountable.

Why this matters: there's no universal "secure" configuration. A whistle-blower platform optimises for anonymity; a banking app optimises for non-repudiation. Designing security means choosing which goals win for this use case.

Tip: New applications (cryptocurrencies, internet voting, privacy-preserving AI) constantly force fresh trade-offs between these goals.