cyber physical system security

Internet Protocol Version 6 is slowly being adopted as the replacement for version 4. Touted as a more secure protocol with increased address space, portability, and greater privacy, research into this and other related protocols has increased, particularly in the context of smart grid, mobile communications, and cloud computing. For the Science of Security community, it is relevant to resiliency, composability, and policy-based governance. But despite improved features, adoption of IPv6 is proceeding at a snail's pace with the possibility it will not be universally deployed for several more decades. One must ask why the reluctance and delay?