What does the I stand for in the CIA triad?

I = Integrity — assurance the data has not been altered in storage or transmission.

I = Integrity

Integrity ensures that data has not been altered during storage or transmission.

How it's achieved:

• Hashing (SHA-256, MD5)
• Digital signatures
• Checksums

Note: MD5 is cryptographically broken (collisions are practical) and is considered legacy only — use SHA-256 or stronger for integrity.

Examples of breaches:

• Man-in-the-middle attacks modifying data
• Malware altering files
• Database tampering

Memory tip: Integrity = "Is it intact?" — the data should be exactly as the sender intended.

Go deeper:

• NIST CSRC glossary: integrity — authoritative: guarding against improper modification; data unaltered since creation/transmit/store.
• Information security / CIA triad (Wikipedia) — integrity in context of the other two pillars.