This week was an interesting one for smart metering announcements. Accent – a Franco-Italian semiconductor design house announced their smart meter on a chip, prompting Jesse Berst of Smart Grid News to enthuse that the “Smart Metering Business has just changed for ever“. Sorry Jesse, but I don’t think so. Elsewhere, in Providence, Rhode Island, New England hackers were convening at QuahogCon to discuss the security of standards. The two announcements provided a good demonstration of the gulf between the promoters of smart metering and the reality of the state of the standards they intend to use. In the same week, ZigBee closed its call for comments on the Technical requirements Document for its Smart Energy Profile, giving the impression that the standard is not far from completion.
The gulf between the enthusiasts and realists is wide. It is worrying that much of the industry is rushing blindly towards deployment, with little understanding of the risks and what can be done to mitigate them.
One of key mantras I keep on hearing repeated when security of the smart meter is raised is “why would anyone bother to hack it?” Josh Wright, talking about ZigBee security at QuahogCon hit the nail on the head when he answered that. “As an attacker, ZigBee lets me interact with the real world – that’s exciting. I can interact with a dam, or natural gas distribution lines. We’re looking at a wireless protocol that lets us interact with real things in the real world – it’s not just credit cards.” The industry forgets the excitement that comes from “because I can” and “real things” And it only needs a few people doing that to fuel scare stories that will kill the whole industry.
Let’s start with Josh. He’s been looking at ZigBee security for some time and reporting on the issues, both of the standard and also of implementations. Like many other wireless standards, ZigBee started off with fairly basic security. Over the years they have added more and better ways of implementing security. However, although these exist within the specification they’re not generally mandated and most ZigBee products on the market don’t implement all of them. Even where they do, there may be errors in the protocol stacks which allow hacking attacks to succeed.
ZigBee’s not alone in this – every wireless standard has gone through the same process. However, the issues only come to light once a standard starts to gain market traction and ship products in volume. Hackers generally don’t bother with obscure or academic standards – they concentrate on the big shippers. Up until now, ZigBee has not been widely used and has escaped scrutiny. With its move into the big time, it’s starting to attract that attention. And that attention is showing that a lot of what is in the market is seriously deficient.
You can see Josh’s presentation and also listen to it. If you are working in the smart energy industry, I’d urge you to find 45 minutes to listen. It is both entertaining and informative. And scary. Robert Cragie has posted some pertinent points about this presentation on his Gridmerge blog.
Last month the ZigBee Alliance asked for comments on its Smart Energy Profile 2.0. It’s part of a new “open” process. I hope that openness will involve publishing all of the comments, so that the industry as a whole can help scrutinise and drive the specification forward. If you missed the deadline, you still have the opportunity to post comments on the draft specification itself, although that round closes on June 4th. If you do submit comments on any security issues, I would urge you to make them public as well, to get wider scrutiny.
ZigBee is by no means alone in this debate. None of the low power wireless contenders vying for this space have had any real degree of external analysis. That’s equally valid for Z-Wave, Wireless M-Bus and Bluetooth low energy. All have written credible specifications, but none have been independently tested. ZigBee is doing the right thing by being open about it, and the others need to follow that example.
Which brings me to the single chip. If that seems an odd jump, it’s not, because the single chip suppliers are selling a dangerous belief, which is that you can make your meter cheaply now, taking advantage of the high levels of integration that are possible, and then upgrade it later. The “jam tomorrow” story of upgradability is a very dangerous sticking plaster that is starting to be used to cover up any worries about security.
Single chips will almost certainly be the way forward. It’s the natural evolutionary path for electronics. But it’s one that is normally taken after a standard settles down, particularly if portions of the standard go into ROM. Because it’s driven by cost reduction, it normally means that the resources on the chip are limited to what is needed today, because unnecessary resource costs money. As a guarantee against future problems, it’s a promise that doesn’t work.
The best specification for a smart meter that I’ve seen is the British Gas one. It mandates upgradeability. It also mandates a recovery procedure from a failed update, which is excellent and more far-sighted than most. And it specifies a product lifetime of twenty years. That’s nothing new for the metering industry. But it represents multiple lifetimes for the wireless industry. And that discrepancy is where we have the problem.
It’s informative to have a brief history lesson in order to understand what twenty years means. If we look back to May 1990, the more advanced of us were running Windows 2.0, although many were still using DOS, or even GEM. I’d recently bought a 286 based PC with a 20MB drive, thinking that would be all I ever needed. No piece of software I buy today would run on that PC.
Digital Mobile telephony was still a dream. No mobile phone from 1990 would work today. Five years later I was lucky enough to own a recently launched Nokia 2010, which still works on the GSM networks. But unless you lived in Europe and were at the bleeding edge of GSM technology, then any phone you might have kept from 1995 is unlikely to work anywhere in the world today.
In terms of short range wireless, everything was still a dream. In 1995, Wi-Fi was seven years away. It’s pre-cursor – 802.11 would arrive the following year, but operating a different frequency, so any PCMICA cards you might have bought then would not work with anything you could buy today. And ZigBee, Bluetooth and 802.15.4 were nowhere on the horizon.
Go back just ten years and there’s not a lot of difference. Most PCs were running Windows 95 or 98 and the first Bluetooth devices were on the market. If you had one of those, it would still probably work with a current Bluetooth product, but at a base level of interoperability. The original security features would still be working, but the more recent enhancements would not. The first Wi-Fi / 802.11b products were beginning to emerge, but with security limited to WEP. They would probably connect with current Wi-Fi products, but it would not be possible to upgrade them to work with the higher security of WPA, which is deemed essential today. And ZigBee was still nowhere to be seen.
We need to regress a mere five years to 2005 to find the first ZigBee release and products. They would be largely incompatible with today’s ZigBee PRO products and could not be upgraded to the security requirements of either of the Smart Energy Profiles.
Bluetooth and GSM have fared best in terms of long term compatibility and security. Whether that is down to luck or judgement can be debated, but that’s not the point. We forget just how quickly technology moves, and how, as it becomes endemic, hackers find flaws either in the standard or the implementations.
The bottom line is that none of these early products can be upgraded to include what is considered best practice even five years later, let alone ten, fifteen or twenty. And there’s the rub. Upgradeability might allow a small improvement to security, but any major flaw is likely to require more resources than a highly optimised single chip contains.
This is a fundamental factor of the rapid progress of technology and the smart meter business needs to understand it. For the future of the industry we need to ensure that the security is as well tested as possible before we start deployments. There are a lot of companies that want to ship in order to make money today, but that puts the entire industry at risk.
The other concern is that wireless upgrades are difficult. I’ve been working in wireless for many years and my advice to customers is never to upgrade a product in the field. With each upgrade a percentage of products will probably fail and that percentage will grow with each new upgrade. Upgrading is not a panacea for cutting corners in the original design; it’s an open cheque-book for future support costs when the upgrade inevitably falls over. It’s a subject that is glossed over, but sufficiently important that I’ve devoted half a chapter to it in my forthcoming book – The essentials of short range wireless.
We must not forget that throughout the history of metering, people have convinced themselves that there are ways of fiddling meters to falsify the readings, from rewiring them, adding magnets, inserting photographic film to act as a brake, using vacuum cleaners (gas meters) or magic devices that alter the spikes in your supply. Once we add digital electronics and a wireless link, this band of amateur hackers will grow from a trickle to a flood as every engineering student tries to find a way of reducing their bill, or turning off their lecture hall lights.
There is no perfect solution – it will become a cat and mouse game, but we need to start from a position of strength. Rushing to market is more likely to be a deployment of weakness, from which it will be difficult to recover.