## The CIA Triad

The cornerstone of Information Security. Every decision balances these three.

1.  **Confidentiality**: Keeping secrets secret.
    *   **Goal**: Only authorized people can read data.
    *   **Tools**: Encryption (AES), Access Control Lists (ACLs), Steganography.
    *   **Failure**: Data Breach (Equifax).
2.  **Integrity**: Trusting the data.
    *   **Goal**: Data has not been tampered with.
    *   **Tools**: Hashing (SHA256), Digital Signatures.
    *   **Failure**: An attacker changing a bank transfer from $10 to $10,000.
3.  **Availability**: Accessing the data.
    *   **Goal**: Systems are up and running.
    *   **Tools**: Redundancy (RAID), Backups, Load Balancers.
    *   **Failure**: DDOS Attack, Ransomware (Encrypting files makes them unavailable).

### The Balancing Act
You cannot have 100% of all three.
*   To make a system perfectly Confidential (unplug internet), you hurt Availability.
*   To make it perfectly Available (Open wifi), you hurt Confidentiality.