January 17, 2025

Posts Comments

Court Rules Email Protected by Fourth Amendment

December 14, 2010 by

Today, the United States Court of Appeals for the Sixth Circuit ruled that the contents of the messages in an email inbox hosted on a provider’s servers are protected by the Fourth Amendment, even though the messages are accessible to an email provider. As the court puts it, “[t]he government may not compel a commercial ISP to turn over the contents of a subscriber’s emails without first obtaining a warrant based on probable cause.”

This is a very big deal; it marks the first time a federal court of appeals has extended the Fourth Amendment to email with such care and detail. Orin Kerr calls the opinion, at least on his initial read, “quite persuasive” and “likely . . . influential,” and I agree, but I’d go further: this is the opinion privacy activists and many legal scholars, myself included, have been waiting and calling for, for more than a decade. It may someday be seen as a watershed moment in the extension of our Constitutional rights to the Internet.

And it may have a more immediate impact on Capitol Hill, because in its ruling the Sixth Circuit also declares part of the Stored Communications Act (SCA) of the Electronic Communications Privacy Act unconstitutional. 18 U.S.C. 2703(b) allows the government to obtain email messages with less than a search warrant. This section has been targeted for amendment by the Digital Due Process coalition of companies, privacy groups, and academics (I have signed on) for precisely the reason now attacked by this opinion, because it allows warrantless government access to communications stored online. I am sure some congressional staffers are paying close attention to this opinion, and I hope it helps clear the way for an amendment to the SCA, to fix a now-declared unconstitutional law, if not during the lame duck session, then early in the next Congressional term.

Update: Other reactions from Dissent and the EFF.

Filed Under: National Security & Surveillance, Privacy & Security Tagged With: ,

Two Stories about the Comcast/Level 3 Dispute (Part 2)

December 10, 2010 by

In my last post I told a story about the Level 3/Comcast dispute that portrays Comcast in a favorable light. Now here’s another story that casts Comcast as the villain.

Story 2: Comcast Abuses Its Market Power

As Steve explained, Level 3 is an “Internet Backbone Provider.” Level 3 has traditionally been considered a tier 1 provider, which means that it exchanges traffic with other tier 1 providers without money changing hands, and bills everyone else for connectivity. Comcast, as a non-tier 1 provider, has traditionally paid Level 3 to carry its traffic to places Comcast’s own network doesn’t reach directly.

Steve is right that the backbone market is highly competitive. I think it’s worth unpacking why this is in a bit more detail. Let’s suppose that a Comcast user wants to download a webpage from Yahoo!, and that both are customers of Level 3. So Yahoo! sends its bits to Level 3, who passes it along to Comcast. And traditionally, Level 3 would bill both Yahoo! and Comcast for the service of moving data between them.

It might seem like Level 3 has a lot of leverage in a situation like this, so it’s worth considering what would happen if Level 3 tried to jack up its prices. There are reportedly around a dozen other tier 1 providers that exchange traffic with Level 3 on a settlement-free basis. This means that if Level 3 over-charges Comcast for transit, Comcast can go to one of Level 3’s competitors, such as Global Crossing, and pay it to carry its traffic to Level 3’s network. And since Global Crossing and Level 3 are peers, Level 3 gets nothing for delivering traffic to Global Crossing that’s ultimately bound for Comcast’s network.

A decade ago, when Internet Service Retailers (to use Steve’s terminology) were much smaller than backbone providers, that was the whole story. The retailers didn’t have the resources to build their own global networks, and their small size meant they had relatively little bargaining power against the backbone providers. So the rule was that Internet Service Retailers charged their customers for Internet access, and then passed some of that revenue along to the backbone providers that offered global connectivity. There may have been relatively little competition in the retailer market, but this didn’t have much effect on the overall structure of the Internet because no single retailer had enough market power to go toe-to-toe with the backbone providers.

Filed Under: Uncategorized

Two Stories about the Comcast/Level 3 Dispute (Part 1)

December 9, 2010 by

Like Steve and a lot of other people in the tech policy world, I’ve been trying to understand the dispute between Level 3 and Comcast. The combination of technical complexity and commercial secrecy has made the controversy almost impenetrable for anyone outside of the companies themselves. And of course, those who are at the center of the action have a strong incentive to mislead the public in ways that makes their own side look better.

So building on Steve’s excellent post, I’d like to tell two very different stories about the Level 3/Comcast dispute. One puts Level 3 in a favorable light and the other slants things more in Comcast’s favor.

Story 1: Level 3 Abuses Its Customer Relationships

As Steve explained, a content delivery network (CDN) is a network of caching servers that help content providers deliver content to end users. Traditionally, Netflix has used CDNs like Akamai and Limelight to deliver its content to customers. The dispute began shortly after Level 3 beat out these CDN providers for the Netflix contract.

Filed Under: Uncategorized

Smart electrical meters and their smart peripherals

December 7, 2010 by

When I was a college undergraduate, I lived in a 1920’s duplex and I recall my roommate and I trying to figure out where our electrical bill was going. He was standing outside by the electrical meter, I was turning things on and off, and we were yelling back and forth so we could sort out which gadgets were causing the wheel to spin faster. (The big power sinks? Our ancient 1950’s refrigerator and my massive-for-the-day 20-inch computer monitor.) Needless to say, this was more difficult than it should have been.

More recently, I got myself a Kill-a-Watt inline power meter which you can use at any power outlet, but it’s a pain. You have to unplug something to measure its usage. People with the big bucks will spring for a Ted 5000 system, which an electrician installs in your breaker box. That’s fantastic, but it’s not cheap or easy.

Today, I’m now the proud new owner of an LS Research “RateSaver”, which speaks ZigBee wireless to the “smart meter” that CenterPoint Energy installed on all the houses in our area. How did I get this thing? I went to a League of Women Voters “meet the candidates” event back in October and CenterPoint Energy had a display there. I asked the guy if I could get one of these things and he said he’s look into it for me. Fast forward two months later, and a box arrived in the mail. New toy!

So what exactly is it? It’s a battery-powered light-weight box with a tolerably readable two-inch monochrome LCD display. As I’m sitting here typing, it’s updating my “current usage” every few seconds and is giving me a number that’s ostensibly accurate to the watt. In the last minute, after I pressed the proper button, it’s been alternating between reading 650-750 watts, and 1400-1500 watts. (Hmm… maybe my fridge consumes 700 watts.) If you leave it alone, the refresh rate slows down to maybe once a minute. Also, it’s sometimes reading “0.000 kW” which is clearly incorrect but it returns to the proper number when I press the button. Wireless range is quite good. I’m on the opposite side of the house as our electrical meter and it’s working fine.

The user interface is all kinds of terrible. In addition to slow button response, the button labels are incorrect. LS Research is apparently just rebranding a Honeywell Home Energy Display (for which the Honeywell manual was included). LS Research apparently rearranged the button labels without changing the corrresponding software. Bravo! Thankfully, the Honeywell manuals have the proper labeling. Also amusing: there’s a message in the system saying that “non-peak price starts at 7:00 PM. Save Money by waiting” when in fact my electrical pricing deal is for a flat rate (which floats with market conditions and is presently $0.0631 per kWh).

Update: I’ve since learned that Honeywell acquired LS Research, so this is something of a transitional screw-up. Welcome to the world of beta products.

Since I’m a security guy, I assumed I’d have to go through some kind of protocol to get the thing activated, and the manual from inside the box describes an activation procedure where you make a phone call to your energy company, giving them the hardware ID numbers of the outdoor smart meter and the indoor display box. Conflicting instructions were also included with my display, describing setup which was as simple as “turn it on and hit the connect button” so I went with the easy instructions. Time passed and the box started working without requiring any additional input from me. I hope that my display box was pre-configured to work exclusively with my house, but this does lead me to wonder about whether they got the security right. (I experimentally turned lights on and off while watching the meter updates and validated that I am, in fact, looking at the usage of my own house.)

At the end of the day, I and everybody else here is now required to pay a $3.24 “advanced meter charge” in order to have all this functionality (which, incidentally, saves the electric company money since it no longer needs human meter readers). Is it worth it? Presumably, at some point I’ll have some kind of variable-priced electricity and I could then hack my refrigerator and air conditioning system to pay attention to the spot price of electricity. If electricity got extra cheap during a five minute window of the hot summer, the controller could then crank the A/C and drop the house an extra few degrees. Of course, if everybody was following this same algorithm, you’d either have insane demand swings, when everybody jumps on to consume cheaper electricity when it’s available, or you’d have to carefully engineer the pricing system such that you had stable demand. Presumably, if you got somebody who understood control theory to design this properly, you could end up incentivizing both demand and pricing to be fairly stable across the space of any given hour of the day.

Probably the biggest benefit of these smart meters will come the next time we have a major hurricane that comes through and knocks out power. Hurricane Ike left my house without power for ten days. At the time, CenterPoint Energy had a vague and useless web site that would give you an idea what neighborhoods were being repaired. Since it was too hot to stay in our house, we stayed instead with a friend who had power and drove by our place every day to see if it had power. This was very frustrating. (I unplugged all my computer equipment, since I didn’t want flakey power to nuke my equipment. Consequently, I couldn’t just do something simple like ping my home computer.) Today, I can log into CenterPoint Energy’s web site and see the power consumption of my house, in 15-minute intervals, and so can the people coordinating the repairs. If they integrated that with a mapping system, they’d have real-time blackout maps, which have obvious value to emergency planners and repair operations coordination.

I just hope they have somebody with a clue looking over the security of their system. (If somebody from CenterPoint reads this: people like me are more than happy to do private security evaluations, red-team exercises, and so forth.)

Future work: there’s a mini USB port on the side of the box. Now I just have to find some documentation. It’s probably bad form for me to go reverse-engineer it myself.

Filed Under: Uncategorized Tagged With: ,

Unpeeling the mystique of tamper-indicating seals

December 7, 2010 by

As computer scientists have studied the trustworthiness of different voting technologies over the past decade, we notice that “security seals” are often used by election officials. It’s natural to wonder whether they really provide any real security, or whether they are just for show. When Professor Avi Rubin volunteered as an election judge (Marylandese for pollworker) in 2006, one of his observations that I found most striking was this:


Avi Rubin
“For example, I carefully studied the tamper tape that is used to guard the memory cards. In light of Hursti’s report, the security of the memory cards is critical. Well, I am 100% convinced that if the tamper tape had been peeled off and put back on, nobody except a very well trained professional would notice it. The tamper tape has a tiny version of the word “void” appear inside it after it has been removed and replaced, but it is very subtle. In fact, a couple of times, due to issues we had with the machines, the chief judge removed the tamper tape and then put it back. One time, it was to reboot a machine that was hanging when a voter was trying to vote. I looked at the tamper tape that was replaced and couldn’t tell the difference, and then it occurred to me that instead of rebooting, someone could mess with the memory card and replace the tape, and we wouldn’t have noticed. I asked if I could play with the tamper tape a bit, and they let me handle it. I believe I can now, with great effort and concentration, tell the difference between one that has been peeled off and one that has not. But, I did not see the judges using that kind of care every time they opened and closed them. As far as I’m concerned, the tamper tape does very little in the way of actual security, and that will be the case as long as it is used by lay poll workers, as opposed to CIA
agents.”

Avi is a first-rate expert in the field of computer security, in part because he’s a good experimentalist—as in, “I asked if I could play with the tamper tape.” To the nonexpert,
security seals have a mystique: there’s this device there, perhaps a special tape or perhaps a thing that looks like a little blue plastic padlock. Most of us encounter these devices in a context where we can’t “play with” them, because that would be breaking the rules: on voting machines, on our electric meter, or whatever. Since we don’t play with them, we can’t tell whether they are secure, and the mystique endures. As soon
as Avi played with one, he discovered that it’s not all that secure.

In fact, we have a word for a piece of tape that only gives the appearance of working:

band-aid: (2) a temporary way of dealing with a problem that will not really solve it (Macmillan Dictionary)

In the last couple of years I’ve been studying security seals on voting machines in New Jersey. For many decades New Jersey law has required that each voting machine be “sealed with a numbered seal”, just after it is prepared for each election (NJSA 19:48-6). Unfortunately it’s hard for legislators to write into the statutes exactly how well these seals must work. Are tamper-indicating seals used in elections really secure? I’ll address that question in my next few articles.

Filed Under: Uncategorized Tagged With: ,