encryption

Encryption protects the confidentiality of data. It is used for data in transit, such as traffic between a browser and server, and stored data, such as laptop files or information in a databaseGlossary · In briefdatabaseA database is a structured collection of data that software can store, retrieve and modify. A database management system controls access to that data.Read more. Someone who intercepts or obtains encrypted data cannot simply read its original contents.

How does encryption work?

An encryption algorithm combines readable data with a key to produce encrypted data. Decryption reverses this process. Security depends both on the chosen algorithm and on how keys are created, stored and exchanged.

With symmetric encryption, sender and recipient use the same secret key. This is fast and suitable for large amounts of data. Asymmetric encryption uses a key pair: a public key and a private key. Data encrypted with the public key can only be decrypted with the corresponding private key. Many systems combine both methods.

What does encryption protect?

Encryption helps prevent unauthorized parties from reading data, for example when someone intercepts network traffic or steals an encrypted laptop. Protection still depends on good key management: someone with the decryption key can generally read the data.

Encryption is reversible, which distinguishes it from hashing. A hash function produces a check value from an input; it is not intended to recover the original input. Hashes are used to verify passwords or detect data changes, among other purposes. Encryption is appropriate when authorized users need to retrieve the original information later.