Incorporating information technology into electronic security systems can bring you two welcome results: improved security capabilities and lower costs. In this article we’ll look at some of the technology breakthroughs that are bringing these results today.
Power Over Ethernet
The telecommunications industry has used a version of electrical power over network connections for many years to allow telephone service to continue i
That requires cameras and network infrastructure that are compliant with IEEE 802.3af, the standard published in mid-2003 that specifies how switches, routers and hubs should deliver power over standard Ethernet cabling to devices like IP phones, security systems and wireless LAN access points. In addition to the security benefits, eliminating separate power cabling to end devices such as cameras can cut installation costs by 50 percent or more.
Axis Communications, Sony and Toshiba have recently introduced PoE-compliant network cameras. “Power is the weakest link in a video surveillance system. PoE strengthens that link,” said Joe Cook, product manager for Toshiba Security & Network Video. Another benefit for video systems is that changing a camera position no longer requires a new AC power installation. PoE makes it easier to experiment over time with camera positions to achieve ideal coverage results. Power can even be extended to selected access control devices.
802.3af defines a way to build Ethernet power-sourcing equipment (such as routers and switches) and powered terminals (such as IP telephones and IP cameras). The specification involves delivering 48 volts of AC power over unshielded twisted-pair wiring. It works with existing cable plant, including Category 3, 5, 5e or 6; horizontal and patch cables; patch-panels; outlets and connecting hardware, without requiring modification.
802.3af power sourcing equipment contains a detection mechanism to prevent sending power to noncompliant devices. Only terminals that present an authenticated PoE signature will receive power, preventing damage to other equipment.
More information on PoE can be obtained from the Power Over Ethernet Web site (see Quicklinks, p. 34), which publishes a regular newsletter related to PoE.
PKI—Old News Is Good News
Public key infrastructure is old news in the IT world. It also has a mixed reputation there, because at first it was heralded as a silver bullet that would almost magically enable all kinds of security capabilities. Instead of fitting PKI solutions to various applications, vendors often sold PKI as a security black box around which companies had to tailor their applications. That was expensive and often unworkable. In many quarters PKI got a bad name, but it wasn’t the basic technology that was the problem, it was the poor application of it. Over time PKI has quietly been resurfacing as part of very specific security applications such as virtual private networks. PKI is a framework that provides a way to use public key encryption to securely send messages over a public network. Public key encryption uses two numerical keys that have a special mathematical relationship to each other. What you encrypt with one key you can decrypt with the other. This allows one key to be kept completely private and the other key to be published or distributed. Whichever key was used to encrypt the data cannot be used to decrypt it.
When security systems used proprietary protocols over closed RS-485 networks, the security of their messages was not an issue. Now that the industry is moving to public protocols over open networks including the Internet, secure messaging is a concern for system security as well as for privacy reasons. Generally speaking, the physical security industry lags behind IT in secure messaging. PKI can provide the solution, and IT companies are starting to step forward with offerings specifically for physical security.