Glossary
Encryption
Encryption is the process of scrambling data with a key so that only someone with the key can read it.
What it means
Encryption is the process of scrambling data with a key so that only someone with the key can read it. It is reversible by design: the right key unscrambles the data back to the original. Encryption protects secrecy — it is what keeps your messages, passwords and banking details unreadable to anyone who intercepts them. Without the key, the scrambled data is meaningless; with the key, it is ordinary again.
How it works
There are two kinds. Symmetric encryption uses one shared key for both scrambling and unscrambling — fast, but the key has to be shared safely first. Asymmetric encryption uses a key pair: a public key anyone can use to scramble a message, and a private key only the recipient holds to unscramble it. In practice the two are combined: asymmetric encryption exchanges a fresh symmetric key, and the symmetric key does the bulk of the work. Modern encryption, such as the AES standard used across the internet, relies on keys so long that trying every possibility is not feasible with any computer that exists — its security rests on the key staying secret, not on the method being hidden.
Example
Imagine two fictional friends, Ana and Ben, who want to exchange letters nobody else can read. Ana writes her letter, locks it in a box with a key, and sends the box to Ben — but Ben needs a copy of the key to open it, and sending the key is itself a risk. That is the symmetric problem. The asymmetric solution: Ben sends Ana an open padlock that only his key can open. Ana locks the box with Ben's padlock and sends it; Ben opens it with his private key. Anyone can lock the box, but only Ben can unlock it.
Common misunderstandings
Two misunderstandings recur. The first is confusing encryption with encoding: Base64 changes how data is written down but protects nothing, because anyone can decode it instantly. The second is confusing encryption with hashing: encryption is reversible, hashing is one-way. An encrypted file can be decrypted; a hashed password cannot be reversed at all.
Related terms
Learn more
- Encryption fundamentals
- Encryption vs hashing
- What is end-to-end encryption?
- Encryption Fundamentals Path
- Back to the full glossary
Last checked: 14 November 2026.
Frequently asked questions
Is encryption the same as hashing?
No. Encryption is reversible with the right key; hashing is one-way and cannot be reversed. Encryption protects secrecy, hashing protects integrity and stores passwords safely.
Is Base64 encryption?
No. Base64 is encoding: it changes how data is written down so it can travel in places that only accept plain text. Anyone can decode it instantly, and it protects nothing.
Can encryption be broken?
Modern encryption with a proper key cannot realistically be broken by trying every key — there are too many. What fails in practice is everything around it: a weak password, a stolen key, an old algorithm, or a mistake in how it was implemented.