Which of the following best defines encryption?

Encryption is best defined as a method for securing data transmissions. It involves converting plaintext data into an unreadable format, known as ciphertext, using an algorithm and a key. This transformation ensures that only authorized parties, who possess the correct decryption key, can access and understand the original data.

The essence of encryption lies in its role in protecting data from unauthorized access during transmission, whether that be over a network or when stored in a database. By securing data in transit, encryption significantly enhances confidentiality and integrity, making it crucial for communication technologies and data protection practices.

Understanding this function clarifies why encryption is specifically tied to securing data transmissions, distinguishing it from other concepts such as data decoding, network traffic management, or database query optimization, which do not inherently involve data protection methods.