Software Architect's Handbook

Encryption

Encryption is the process of transforming ordinary data, which is referred to as plaintext, into a format that is unreadable, which is referred to as ciphertext. This prevents unauthorized parties from accessing it. Data is encrypted using an encryption algorithm in conjunction with an encryption key. Larger key sizes result in greater encryption strength but make the process of encryption/decryption slower.

Data that is encrypted can be reverted to its original value. Encryption is used over hashing when there is a need to know the decrypted value. For example, the encryption is used to send a secure message to someone, it must be possible for the recipient to decrypt the message or it will be useless. Decryption is the process ...