DATA SECURITY
A Security Domain is generally a collection of computers, servers, and users that are trusted to exchange data and are protected by network security filters, inspectors, and firewalls. However, when data leaves one security domain and enters another, the new domain, is by default, not trusted and the data must be decrypted prior to transfer, thereby losing protection. Modern network architectures make use of transport protocols such as SSL (Secure Sockets Layer), TLS (Transport Layer Security), and VPN (Virtual Private Network) to stretch the boundary of the security domain and temporarily encompass visiting machines to safely exchange data.
