Data Encryption

Term: Data Encryption

Definition:
Data encryption is used to protect your data. Ciphers are the mechanism by which Backup4all encrypts and decrypts data being sent to SFTP server. A block cipher is the most common form of symmetric key algorithms (e.g. DES, 3DES, Blowfish, AES, and Twofish).
These operate on a fixed size block of data, use a single, secret, shared key, and generally involve multiple rounds of simple, non-linear functions. The data at this point is encrypted and cannot be reversed without the shared key.

When Backup4all establishes a connection with the SFTP server, they must agree which cipher they will use to encrypt and decrypt data. The server generally presents a list of the ciphers it supports, and Backup4all then selects the first cipher in its list that matches one in the server’s list.

Backup4all and the SFTP server use the same session key to encrypt and decrypt data although a different key is used for the send and receive channels. Session keys are generated after host authentication is successfully performed but before user authentication so that usernames and passwords can be sent encrypted. The session keys may be replaced at regular intervals during the session and are destroyed at its conclusion.

Related terms: Data Encryption, SFTP, Backup4all, Ciphers