Encryption:
In cryptography, encryption is the process of encoding messages or information in such a way that only authorized parties can read it.[1] Encryption does not of itself prevent interception, but denies the message content to the interceptor.[2]:374 In an encryption scheme, the message or information, referred to as plaintext, is encrypted using an encryption algorithm, generating ciphertext that can only be read if decrypted.[2] For technical reasons, an encryption scheme usually uses a pseudo-random encryption key generated by an algorithm. It is in principle possible to decrypt the message without possessing the key, but, for a well-designed encryption scheme, large computational resources and skill are required. An authorized recipient can easily decrypt the message with the key provided by the originator to recipients, but not to unauthorised interceptors.
Decryption is the process of converting
encrypted data back into its original form, so it can be understood. Encryption
and decryption should not be
confused with encoding and decoding, in which data is converted from one form
to another but is not deliberately altered so as to conceal its content. Decryption
is generally the reverse process of encryption. It is
the process of decoding the data which has
been encrypted into a secret format. An authorized user can only decrypt data
because decryption requires a secret key or password.