What is the purpose of encryption in data transmission?

Encryption in data transmission primarily serves the purpose of encoding messages so that only authorized parties can read them. By transforming the original data into a secure format using algorithms, encryption ensures that even if the data is intercepted during transmission, it remains unintelligible to unauthorized users.

This process protects sensitive information, such as personal data or confidential corporate information, from potential threats and breaches that could occur in transit over networks. The use of encryption creates a layer of security that is essential in maintaining privacy and data integrity, especially in environments where cyber threats are prevalent.

The other options address different aspects of data handling but do not accurately convey the primary function of encryption. Compression is related to reducing file size for faster transmission but does not inherently provide security. Similarly, increasing data transfer speed is not a function of encryption, nor is facilitating backup of sensitive data, which focuses more on data storage and retrieval than on protecting the data during transmission.