What is defined as a data security technique where machine-readable data are scrambled?

The correct answer is encryption, which is a data security technique used to protect sensitive information by transforming it into a format that is unreadable to unauthorized users. This process involves scrambling the original data using algorithms and a key, making it secure against interception or unauthorized access.

Encryption ensures that even if data is intercepted during transmission or accessed without permission, it cannot be easily understood or used without the necessary decryption key. This technique is critical in maintaining confidentiality and integrity in data communications, particularly in financial transactions and personal information exchanges.

In contrast, encoding refers to transforming data into a different format for specific purposes, such as data representation or consistency, but it does not provide security since it can be easily reversed without the need for a key. Hashing is a process that converts data into a fixed-size string of characters, typically for data integrity verification, but it is not meant for data concealment and cannot be reversed back to the original data. Decoding simply reverses the encoding process, returning data to its original state, and does not involve any scrambling or security measures. Thus, encryption stands out as the key technique for securing data by making it incomprehensible to anyone without the proper authorization.