Which of the following most accurately defines encryption?

Encryption is fundamentally about transforming data in a way that allows only authorized parties to access that information in its original form. The definition that states "changing a message so it can only be easily read by the intended recipient" captures this essence perfectly.

Encryption is designed not just to modify a message but to ensure that regardless of how complex the underlying processes or algorithms may be, the primary goal is to protect the confidentiality of the data. By doing so, it enables only the intended recipient, who possesses the correct decryption key, to convert the encrypted data back into its readable form. This explanation emphasizes the core purpose of encryption, which is to maintain privacy and secure communication between parties.

In contrast, while changing a message using complex mathematics, applying keys to plain text, and making binary changes to a message to conceal it are all components or aspects of the encryption process, they do not encompass the broader objective of ensuring that only the intended recipient can easily understand the message. These other descriptions could be seen as partial views on what encryption entails but lack the clarity and specificity regarding the end goal of ensuring confidentiality and exclusive access.