What is encryption and how does it protect data?

Short answer

Encryption is the process of converting plaintext into ciphertext using mathematical algorithms and keys. Only parties with the correct key can decrypt and read the data.

How it works

Encryption algorithms like AES, ChaCha20, and RSA apply complex mathematical transformations to data. Symmetric encryption uses one shared key for both encryption and decryption. Asymmetric encryption uses a public key to encrypt and a private key to decrypt.

Modern encryption relies on key strength and algorithm security rather than obscurity. AES-256 is currently the gold standard for symmetric encryption.

Example

When you send an encrypted email, your message is scrambled before leaving your device. Even if an attacker intercepts the transmission, they see only meaningless data without the decryption key.

Why it matters

Encryption protects data at rest on disks, in transit across networks, and in use within secure enclaves. It is the last line of defense when perimeter security fails and is legally required for many compliance frameworks.