Security boundaries in the IT world are changing, porous, often imaginary lines.

A security boundary is a demarcation that delineates sovereign or administrative borders that dictate who controls what.

Boundary owners are supposed to protect the assets inside their domains against all other unauthorized incursions.
Security boundaries are important. Nearly every war is fought over one.[ See Roger Grimes’ free and almost foolproof way to check for malware. | Discover how to secure your systems with InfoWorld’s Security newsletter. ]

For many decades, boundaries were dictated by traditional firewalls or routers.

The firewall or router owner defined, usually by IP address, the inside and outside legs — or if they required one, a DMZ shared by both sides.

All traffic traversing one side to another underwent inspection and was blocked if not allowed.To read this article in full or to leave a comment, please click here