The DES_DECRYPT() function decrypts a "Binary string" with the given "Key" using the triple-DES algorithm.
Without a "Key" argument, the key number contained in the first character of the "Binary string" is used.
If "Binary string" was encrypted with a key number and that number is provided in the "Key" argument, the function returns NULL.
If "Key" is a string argument, the specified string is used to decrypt "Binary string".
Returns a string or NULL if an error occurs.
If "Binary string" contains no characters, an empty string is returned.
If the value of the "Binary string" argument is NULL, the DES_DECRYPT() function returns NULL.
This feature only works if MariaDB has been configured with TLS support.
As of MariaDB 10.10, this feature is deprecated and will be removed in future releases.
This feature is not present in MySQL 8.0.
The function DES_ENCRYPT() can be used for encryption.