June 25, 2017

Archives for July 2003

Why Aren't Virus Attacks Worse?

Dan Simon notes a scary NYT op-ed, “Terrorism and the Biology Lab,” by Henry C. Kelly. Kelly argues convincingly that ordinary molecular biology students will soon be able to make evil bio-weapons. Simon points out the analogy to computer viruses, which are easily made and easily released. If serious bio-weapons become as common as computer viruses, we are indeed in deep trouble.

Eric Rescorla responds by noting that the computer viruses we actually see do relatively little damage, at least compared to what they might have done. Really malicious viruses, that is, ones engineered to do maximum damage, are rare. What we see instead are viruses designed to get attention and to show that the author could have done damage. The most likely explanation is that the authors of well-known viruses have written them as a sort of (twisted) intellectual exercise rather than out of spite. [By the way, don’t miss the comments on Eric’s post.]

This reminds me of a series of conversations I had a few years ago with a hotshot mo-bio professor, about the national-security implications of bio-attacks versus cyber-attacks. I started out convinced that the cyber-attack threat, while real, was overstated; but bio-attacks terrified me. He had the converse view, that bio-attacks were possible but overhyped, while cyber-attacks were the real nightmare scenario. Each of us tried to reassure the other that really large-scale malicious attacks of the type we knew best (cyber- for me, bio- for him) were harder to carry out, and less likely, than commonly believed.

It seems to me that both of us, having spent many days in the lab, understood how hard it really is to make a novel, sophisticated technology work as planned. Since nightmare attacks are, by definition, novel and sophisticated and thus not fully testable in advance, the odds are pretty high that something would go “wrong” for the attacker. With a better understanding of how software can go wrong, I fully appreciated the cyber-attacker’s problem; and with a better understanding of how bio-experiments can go wrong, my colleague fully appreciated the bio-attacker’s problem. If there is any reassurance here, it is in the likelihood that any would-be attacker will miss some detail and his attack will fizzle.

Aimster Loses

As expected, the Seventh Circuit Court of Appeals has upheld a lower court’s temporary injunction against the Aimster file-sharing service. The Court’s opinion was written by Judge Richard Posner.

I noted three interesting things in the opinion. First, the court seemed unimpressed with Aimster’s legal representation. At several points the opinion notes arguments that Aimster could have made but didn’t, or important factual questions on which Aimster failed to present any evidence. For example, Aimster apparently never presented evidence that its system is ever used for noninfringing purposes.

Second, the opinion states, in a surprisingly offhand manner, that it’s illegal to fast-forward through the commercials when you’re replaying a taped TV show. “Commercial-skipping … amounted to creating an unauthorized derivative work … namely a commercial-free copy that would reduce the copyright owner’s income from his original program…”

Finally, the opinion makes much of the fact that Aimster traffic uses end-to-end encryption so that the traffic cannot be observed by anybody, including Aimster itself. Why did Aimster choose a design that prevented Aimster itself from seeing the traffic? The opinion assumes that Aimster did this because it wanted to remain ignorant of the infringing nature of the traffic. That may well be the real reason for Aimster’s use of encryption.

But there is another good reason to use end-to-end encryption in such a service. Users might want to transfer sensitive but noninfringing materials. If so, they would want those transfers to be protected by encryption. The transfer could in principle be decrypted and then reencrypted at an intermediate point such as an Aimster server. This extra decryption would indeed allow Aimster to detect infringement, but it would have several enginering disadvantages, including the extra processing time required to do the extra decryption and reencryption, and the risk of the data being compromised in case of a break-in at the server. The opinion hints at all of this; but apparently Aimster did not offer arguments on this point.

The opinion says, instead, that a service provider has a limited duty to redesign a service to prevent infringement, where the cost of adopting a different design must be weighted against the amount of infringement that it would prevent.

Even when there are noninfringing uses of an Internet file-sharing service, moreover, if the infringing uses are substantial then to avoid liability as a contributory infringer the provider of the service must show that it would have been dispropotionately costly for him to eliminate or at least reduce substantially the infringing uses.

And so one more reading of the Supreme Court’s Sony Betamax decision is now on the table.