Users in the two offices would like to access each other's file servers over the internet. What control would provide confidentiality for those communications?

Virtual private networks (VPNs) provide secure communications channels over otherwise insecure networks (such as the Internet) using encryption. If you establish a VPN connection between the two offices, users in one office could securely access content located on the other office's server over the Internet. Digital signatures are used to provide nonrepudiation, not confidentiality. Virtual LANs (VLANs) provide network segmentation on local networks but do not cross the Internet. Digital content management solutions are designed to manage web content, not access shared files located on a file server.