October 6, 2022

Archives for October 2009

Sequoia Announces Voting System with Published Code

Sequoia Voting Systems, one of the major e-voting companies, announced Tuesday that it will publish all of the source code for its forthcoming Frontier product. This is great news–an important step toward the kind of transparency that is necessary to make today’s voting systems trustworthy.

To be clear, this will not be a fully open source system, because it won’t give users the right to modify and redistribute the software. But it will be open in a very important sense, because everyone will be free to inspect, analyze, and discuss the code.

Significantly, the promise to publish code covers all of the systems involved in running the election and reporting results, “including precinct and central count digital optical scan tabulators, a robust election management and ballot preparation system, and tally, tabulation, and reporting applications”. I’m sure the research community will be eager to study this code.

The trend toward publishing election system source code has been building over the last few years. Security experts have long argued that public scrutiny tends to increase security, and is one of the best ways to justify public trust in a system. Independent studies of major voting vendors’ source code have found code quality to be disappointing at best, and vendors’ all-out resistance to any disclosure has eroded confidence further. Add to this an increasing number of independent open-source voting systems, and secret voting technologies start to look less and less viable, as the public starts insisting that longstanding principles of election transparency be extended to election technology. In short, the time had come for this step.

Still, Sequoia deserves a lot of credit for being the first major vendor to open its technology. How long until the other major vendors follow suit?

DRM by any other name: The latest from Hollywood

Sunday’s New York Times had an article, Studios’ Quest for Life After DVDs. To nobody’s surprise, consumers want to have convenient access to “their” media, wherever they happen to be, without all the annoying restrictions that come into play when you add DRM to the picture. To many people’s surprise, sales of DVDs (much less Blu-ray) are in trouble.

In the third quarter, studios’ home entertainment divisions generated about $4 billion, down 3.2 percent from a year ago, according to the Digital Entertainment Group, a trade consortium. But digital distribution contributed just $420 million, an increase of 18 percent.

Given that DVDs are really a luxury good (versus, say, food or electricity), the 3.2 percent drop seems like Hollywood is getting off easy. The growth in digital distribution is clearly getting attention, though. What’s going on here? I imagine several things. People sometimes miss their shows. Maybe the cable went out. Maybe the TiVo crashed. Maybe they’re on the road. Drop $2 at the iTunes Store and you’re good to go. That’s attractive and it’s real money.

Still, the article goes on to talk about… yet more DRM.

Standing in the way are technology hurdles — how to let consumers play a video on various devices without letting them share it with 10,000 close friends on a pirate site — and the reluctance of studios to cooperate too closely with rivals for reasons of antitrust scrutiny and sheer competitiveness.

And piracy, at least conceptually, would be less of a worry. The technology [Disney’s Keychest] rests on cloud computing, in which huge troves of data are stored on remote servers so users have access from anywhere. Movies would be streamed from the cloud and never downloaded, making them harder to pirate.

Of course, this is baloney. If it’s going to work on my iPhone while I’m sitting in an airplane, the entire video needs to be stored there in advance. Furthermore, if the video is supposed to be “high definition,” that’s a bare minimum of 5 megabits/sec. (Broadcast HD is 20 megabits/sec and Blu-ray is 48 megabits/sec.) Most home DSL or cable modem connections either will never go that fast, or certainly cannot maintain those speeds without hiccups, particularly when sharing the line with other users. To do high quality video, you either have to have a real broadcast medium (cable, over-the-air, or satellite) or you have to download in advance and store on a hard drive.

And, of course, once you’ve stored the video, it’s just not that hard to extract it. And it always will be. The challenge for Hollywood is to change the incentives of the game. Maybe sell me a flat-rate subscription. Maybe bundle it with my DSL provider. But make the experience compelling enough and cheap enough, and I’ll do it. I regularly extract video from my TiVo and copy it to my iPhone via third-party software. It’s practically painless and it happens to yield files that I could share with the world, but I don’t. Why? Because there’s real downside (I’d rather not get sued, thanks), and no particular upside.

So, dearest Hollywood executive, consider that selling your content for a reduced price, with no DRM, is not the same thing as “giving it away.” If you allow third-parties to license your content and distribute it without DRM, you can still go after the “pirates”, yet you’ll allow normal people to enjoy your work without making them suffer for it. Yes, you may have kids copying content from one to the next, just like we used to do dubbing cassette tapes, but those incremental losses can and will be offset by the incremental gains of people enjoying your work and hitting the “buy” button.

There’s anonymity on the Internet. Get over it.

In a recent interview prominent antivirus developer Eugene Kaspersky decried the role of anonymity in cybercrime. This is not a new claim – it is touched on in the Commission on Cybersecurity for the 44th Presidency Report and Cybersecurity Act of 2009, among others – but it misses the mark. Any Internet design would allow anonymity. What renders our Internet vulnerable is primarily weakness of software security and authentication, not anonymity.

Consider a hypothetical of three Internet users: Alice, Bob, and Charlie. If Alice wants to communicate anonymously with Charlie, she may relay her messages through Bob. While Charlie knows Bob is an intermediary, Charlie does not know with whom he is ultimately communicating. For even greater anonymity Alice can pass her messages through multiple Bobs, and by applying cryptography she can ensure no individual Bob can piece together that she is communicating with Charlie. This basic approach to anonymity is remarkable in its independence of the Internet’s design: it only requires that some Bob(s) can and do run intermediary software. Even on an Internet where users could verify each other’s identity this means of anonymity would remain viable.

The sad state of software security – the latest DHS weekly bulletin alone identified over 40 “high severity” vulnerabilities – is what enables malicious users to exploit the Internet’s indelible capacity for anonymity. Modifying the prior hypothetical, suppose Alice now wants to spam, phish, denial of service (DoS) attack, or hack Charlie. After compromising Bob’s computer with malicious software (malware), Alice can send emails, host websites, and launch DoS attacks from it; Charlie knows Bob is apparently misbehaving, but has no means of discovering Alice’s role. Nearly all spam, phishing, and DoS attacks are now perpetrated with networks of compromised computers like Bob’s (botnets). At the writing of a July 2009 private sector report, just five botnets sourced nearly 75% of spam. Worse yet, botnets are increasingly self-perpetuating: spam and phishing websites propagate malware that compromises new computers for the botnet.

Shortcomings in authentication, the means of proving one’s identity either when necessary or at all times, are a secondary contributor to the Internet’s ills. Most applications rely on passwords, which are easily guessed or divulged through deception – the very mechanisms of most phishing and account hijacking. There are potential technical solutions that would enable a user to authenticate themselves without the risk of compromising accounts. But any approach will be undermined by weaknesses in underlying software security when a malicious party can trivially compromise a user’s computer.

The policy community is already trending towards acceptance of Internet anonymity and refocusing on software security and authentication; the recent White House Cyberspace Policy Review in particular emphasizes both issues. To the remaining unpersuaded, I can only offer at last a truism: There’s anonymity on the Internet. Get over it.

Net Neutrality: When is Network Management "Reasonable"?

Last week the FCC released its much-awaited Notice of Proposed Rulemaking (NPRM) on network neutrality. As expected, the NPRM affirms past FCC neutrality principles, and adds two more. Here’s the key language:

1. Subject to reasonable network management, a provider of broadband Internet access service may not prevent any of its users from sending or receiving the lawful content of the user’s choice over the Internet.

2. Subject to reasonable network management, a provider of broadband Internet access service may not prevent any of its users from running the lawful applications or using the lawful services of the user’s choice.

3. Subject to reasonable network management, a provider of broadband Internet access service may not prevent any of its users from connecting to and using on its network the user’s choice of lawful devices that do not harm the network.

4. Subject to reasonable network management, a provider of broadband Internet access service may not deprive any of its users of the user’s entitlement to competition among network providers, application providers, service providers, and content providers.

5. Subject to reasonable network management, a provider of broadband Internet access service must treat lawful content, applications, and services in a nondiscriminatory manner.

6. Subject to reasonable network management, a provider of broadband Internet access service must disclose such information concerning network management and other practices as is reasonably required for users and content, application, and service providers to enjoy the protections specified in this part.

That’s a lot of policy packed into (relatively) few words. I expect that my colleagues and I will have a lot to say about these seemingly simple rules over the coming weeks.

Today I want to focus on the all-purpose exception for “reasonable network management”. Unpacking this term might tell us a lot about how the proposed rule would operate.

Here’s what the NPRM says:

Reasonable network management consists of: (a) reasonable practices employed by a provider of broadband Internet access to (i) reduce or mitigate the effects of congestion on its network or to address quality-of-service concerns; (ii) address traffic that is unwanted by users or harmful; (iii) prevent the transfer of unlawful content; or (iv) prevent the unlawful transfer of content; and (b) other reasonable network management practices.

The key word is “reasonable”, and in that respect the definition is nearly circular: in order to be “reasonable”, a network management practice must be (a) “reasonable” and directed toward certain specific ends, or (b) “reasonable”.

In the FCC’s defense, it does seek comments and suggestions on what the definition should be, and it does say that it intends to make case-by-case determinations in practice, as it did in the Comcast matter. Further, it rejects a “strict scrutiny” standard of the sort that David Robinson rightly criticized in a previous post.

“Reasonable” is hard to define because in real life every “network management” measure will have tradeoffs. For example, a measure intended to block copyright-infringing material would in practice make errors in both directions: it would block X% (less than 100%) of infringing material, while as a side-effect also blocking Y% (more than 0%) of non-infringing material. For what values of X and Y is such a measure “reasonable”? We don’t know.

Of course, declaring a vague standard rather than a bright-line rule can sometimes be good policy, especially where the facts on the ground are changing rapidly and it’s hard to predict what kind of details might turn out to be important in a dispute. Still, by choosing a case-by-case approach, the FCC is leaving us mostly in the dark about where it will draw the line between “reasonable” and “unreasonable”.

Intractability of Financial Derivatives

A new result by Princeton computer scientists and economists shows a striking application of computer science theory to the field of financial derivative design. The paper is Computational Complexity and Information Asymmetry in Financial Products by Sanjeev Arora, Boaz Barak, Markus Brunnermeier, and Rong Ge. Although computation has long been used in the financial industry for program trading and “the thermodynamics of money”, this new paper applies an entirely different kind of computer science: Intractability Theory.

A financial derivative is a contract specifying a payoff calculated by some formula based on the yields or prices of a specific collection of underlying assets. Consider the securitization of debt: a CDO (collateralized debt obligation) is a security formed by packaging together hundreds of home mortgages. The CDO is supposedly safer than the individual mortgages, since it spreads the risk (not every mortgage is supposed to default at once). Furthermore, a CDO is usually divided into “senior tranches” which are guaranteed not to drop in value as long as the total defaults in the pool does not exceed some threshhold; and “junior tranches” that are supposed to bear all the risk.

Trading in derivatives brought down Lehman Brothers, AIG, and many other buyers, based on mistaken assumptions about the independence of the underlying asset prices; they underestimated the danger that many mortgages would all default at the same time. But the new paper shows that in addition to that kind of danger, risks can arise because a seller can deliberately construct a derivative with a booby trap hiding in plain sight.

It’s like encryption: it’s easy to construct an encrypted message (your browser does this all the time), but it’s hard to decrypt without knowing the key (we believe even the NSA doesn’t have the computational power to do it). Similarly, the new result shows that the seller can construct the CDO with a booby trap, but even Goldman Sachs won’t have enough computational power to analyze whether a trap is present.

The paper shows the example of a high-volume seller who builds 1000 CDOs from 1000 asset-classes of home mortages. Suppose the seller knows that a few of those asset classes are “lemons” that won’t pay off. The seller is supposed to randomly distribute the asset classes into the CDOs; this minimizes the risk for the buyer, because there’s only a small chance that any one CDO has more than a few lemons. But the seller can “tamper” with the CDOs by putting most of the lemons in just a few of the CDOs. This has an enormous effect on the senior tranches of those tampered CDOs.

In principle, an alert buyer can detect tampering even if he doesn’t know which asset classes are the lemons: he simply examines all 1000 CDOs and looks for a suspicious overrepresentation of some of the asset classes in some of the CDOs. What Arora et al. show is that is an NP-complete problem (“densest subgraph”). This problem is believed to be computationally intractable; thus, even the most alert buyer can’t have enough computational power to do the analysis.

Arora et al. show it’s even worse than that: even after the buyer has lost a lot of money (because enough mortgages defaulted to devalue his “senior tranche”), he can’t prove that that tampering occurred: he can’t prove that the distribution of lemons wasn’t random. This makes it hard to get recourse in court; it also makes it hard to regulate CDOs.

Intractability Theory forms the basis for several of the technologies discussed on Freedom-to-Tinker: cryptography, digital-rights management, watermarking, and others. Perhaps now financial policy is now another one.