Resposta de referência
The CIA triad stands for Confidentiality, Integrity, and Availability, and it's the foundation of almost every decision in cyber security. Whether you're setting a password policy, responding to an incident, or building access rules, you're thinking in terms of one or more of these three goals.
Confidentiality is about keeping data private. Only the right people should be able to access sensitive information, whether it's customer records, login credentials, or internal emails. Common protections include encryption, user authentication, role-based access, and even physical security such as keeping servers in a locked room.
Integrity means the data hasn't been changed, tampered with, or corrupted, either by accident or on purpose. A system log, for example, has to be trustworthy if you're investigating a breach. Tools like cryptographic hashes, digital signatures, and file integrity monitoring help ensure that what you're looking at is exactly what it was meant to be.
Availability means systems and data are accessible when needed. This is especially critical in healthcare, finance, and emergency services where if users can't access the tools or information they rely on, then the impact can be serious. Protections here include backup systems, load balancing, and mitigation against DDoS attacks or ransomware that locks users out.
An important thing to also understand is that these three pillars often come into tension with each other due to their tradeoffs.
For example: You might encrypt everything to protect confidentiality, but that could slow down a system and hurt availability. Or you might open up system access to make it more available, but that could increase risk to both integrity and confidentiality. Good security decisions balance those tradeoffs.