How does a Virtual Private Network (VPN) ensure confidentiality for data transmission?

A Virtual Private Network (VPN) ensures confidentiality for data transmission primarily through the use of encryption. When data is transmitted over a VPN, it is scrambled into an unreadable format that can only be converted back into its original form by someone with the correct decryption key. This encryption process effectively secures the data, making it extremely difficult for unauthorized individuals or entities to intercept and read the information being transmitted over the network.

While stronger password authentication is important for access control, it does not directly secure the data being transmitted. Compressing data can help with speed and efficiency of network traffic but does not provide confidentiality. Filtering incoming traffic can enhance security by blocking unwanted data, but it also does not directly protect the confidentiality of data in transit.

Hence, encryption is the key mechanism through which VPNs maintain the confidentiality of data, ensuring that even if the data is intercepted, it cannot be read without the proper keys for decryption.