Which of the following is an example of a public network?

• A. A corporate VPN
• B. The Internet
• C. A private LAN
• D. An intranet

Answer: (B)

A public network is one that isn’t owned or controlled by a single organization and is accessible to anyone with a connection. The Internet fits this description as a global, open network used by countless users and organizations.

A corporate VPN, while it may travel over the Internet, creates a private, secure tunnel into the company’s network, so it’s considered a private connection rather than a public network. A private LAN is a local network confined to an organization, and an intranet is an internal site or network for internal use. Both are private by design.

In PCI DSS terms, data security over networks matters regardless of public or private status, but recognizing the Internet as a public network helps explain why strong encryption and proper access controls are essential when transmitting cardholder data over any network.