What technology ensures secure remote connectivity to a network?

A Virtual Private Network (VPN) is the technology that ensures secure remote connectivity to a network. It creates an encrypted tunnel over the internet, allowing users to send and receive data as if they were directly connected to a private network. This encryption secures the data from eavesdropping, making it very difficult for unauthorized parties to access the transmitted information. By using a VPN, remote users can access network resources securely, maintaining confidentiality and integrity while connected to potentially unsafe public networks.

The other technologies listed serve different purposes. Remote Desktop Protocol, while used for connecting to remote machines, does not inherently provide the same level of network security as a VPN since its primary function is to enable a graphical interface. A Network Firewall is designed to control incoming and outgoing traffic and protect the network from unauthorized access, but it does not provide secure remote access on its own. Secure Socket Layer (SSL) is a protocol for encrypting information over the internet but is typically used for securing web communications rather than establishing remote network access.