Encryption
Encryption is the process of converting data into a form that only the person holding the right key can read. It is the foundation of modern digital security.
| In brief | The process of converting data into a form that only the person holding the right key can read. |
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| Technical definition | Turning data into an unreadable form using an algorithm and a key (encryption) and reversing it with the correct key (decryption). |
| Everyday example | The padlock symbol in a browser's address bar shows that the connection between you and that site is encrypted. |
| Why it matters | The security of digital life, from banking to messaging, rests on encryption; without it no transaction over the internet could be carried out safely. |
| Common misconceptions |
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The locked box comparison
You can think of encryption as putting a message into a locked box: whoever's hands the box passes through on the way, anyone without the key cannot read what is inside. Technically, what happens is that the data is turned by a mathematical method into a sequence that looks meaningless; the right key reverses that transformation. Security rests on the secrecy of the key rather than the secrecy of the method; the methods are publicly known and publicly examined.
You use it every day without noticing
The padlock symbol in your browser's address bar shows that the traffic between you and the site is encrypted; this is what makes internet banking safe. "End-to-end encryption" in messaging applications means the message can be read only by the two ends, you and the person you are writing to, and not even by the servers in between. A phone's screen lock works together with the encryption of the data inside the device, and the Wi-Fi password on your wireless router encrypts the traffic at home.
Commonly misunderstood
The view that "encryption is a criminal's tool" is widespread but misleading: encryption protects banking, health records and private correspondence, and it is a technology that works for the ordinary user. The second misconception is the belief that "encrypted data can never be broken": modern methods, used correctly, are accepted as unbreakable in practice; but weak passwords, un-updated software and human-centred attacks such as phishing can go around encryption altogether. Encryption is a strong lock; it cannot stop the door being left open.
Related terms: Two-Step Verification, Wireless Router, Backup