Technology
How does encryption work?
Encryption works by scrambling readable data into ciphertext using a mathematical algorithm and a key. Only someone with the matching key can reverse it — and modern encryption relies on math that's easy one way but practically impossible to undo without the key.
See it in motion.
Watch a 2-minute animated lesson that shows exactly how encryption works.
Step by step
- 1An algorithm plus a key transform plaintext into unreadable ciphertext.
- 2Symmetric encryption uses the same key to lock and unlock.
- 3Public-key (asymmetric) encryption uses a public key to encrypt and a private key to decrypt.
- 4Its security rests on math problems that are infeasible to reverse without the key.
Frequently asked questions
- What is a key in encryption?
- A secret value the algorithm uses to scramble and unscramble data; without it, ciphertext is unreadable.
- How does public-key encryption work?
- Anyone can encrypt with your public key, but only your private key can decrypt — so you never share the secret.
- Why is encryption hard to break?
- It relies on math (like factoring huge numbers) that would take impractically long to reverse without the key.