Key (cryptography)

In cryptography, a key (or cryptographic key) is a piece of information that allows control over the encryption or decryption process.

There are two basic types of cryptographic algorithms.

• Symmetric algorithm: If there is just one key for encrypting and decrypting, the algorithm is called symmetric.
• Asymmetric algorithm: If there are two different keys, each of which can be used only to encrypt data or only to decrypt it, the algorithm is called asymmetric. If an algorithm is asymmetric, one person publishes a key and accepts messages encrypted with that key. Anyone can encrypt a message, but only the person who owns the other key can decrypt it. This is how online stores, banks, etc., work.