Encryption

Encryption transforms data into ciphertext to keep it confidential.

Updated: 2026-03-05

Definition

Encryption protects confidentiality by converting plaintext into ciphertext using a key.

Decryption reverses the process when you have the correct key.

Key points

Confidentiality (not integrity by itself)
Symmetric = one key, fast; asymmetric = key pair, slower
Key management is often the hardest part

Common mistakes

Assuming encryption solves integrity (you may need signatures/HMAC).
Poor key storage/rotation (keys become the real target).

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