Really:

Experts say the precipitous drop-off in spam comes from Internet providers unplugging McColo Corp., a hosting provider in Northern California that was the home base for machines responsible for coordinating the sending of roughly 75 percent of all spam each day.

Certainly this won't last:

Bhandari said he expects the spam volume to recover to normal levels in about a week, as the spam operations that were previously hosted at McColo move to a new home.

"We're seeing a slow recovery," Bhandari. "We fully expect this to recover completely, and to go into the highest ever spam period during the upcoming holiday season."

But with all the talk of massive botnets sending spam, it's interesting that most of it still comes from hosting services. You'd think this would make the job of detecting spam a lot easier.

Mostly sardines, but some squid.

Interview with me from Datamation.

My Guardian article also appeared in The Hindu. Nothing I haven't said before.

Not a threat people think a lot about.

It's a tough security trade-off. Guests lose their hotel room keys, and the hotel staff needs to be accommodating. But at the same time, they can't be giving out hotel room keys to anyone claiming to have lost one. Generally, hotels ask to see some ID before giving out a replacement key and, if the guest doesn't have his wallet with him, have someone walk to the room with the key and check their ID.

This normally works pretty well, but there's a court case in Brisbane right now about a hotel giving a room key to someone who ended up sexually attacking the woman who had rented the room.

In civil action launched yesterday, the woman alleges the man was given the spare access key to her room by a hotel staffer.

The article doesn't say what kind of authentication the hotel requested or received.

Using the incremental update feature of pdf files to watch a malware author create his exploit.

I was in Dubai last weekend for the World Economic Forum Summit on the Global Agenda. (I was on the "Future of the Internet" council; fellow council members Ethan Zuckerman and Jeff Jarvis have written about the event.)

As part of the United Arab Emirates, Dubai censors the Internet:

The government of the United Arab Emirates (UAE) pervasively filters Web sites that contain pornography or relate to alcohol and drug use, gay and lesbian issues, or online dating or gambling. Web-based applications and religious and political sites are also filtered, though less extensively. Additionally, legal controls limit free expression and behavior, restricting political discourse and dissent online.

More detail here.

What was interesting to me about how reasonable the execution of the policy was. Unlike some countries -- China for example -- that simply block objectionable content, the UAE displays a screen indicating that the URL has been blocked and offers information about its appeals process.

Excellent paper on the economics of spam. The authors infiltrated the Storm worm and monitored its doings.

After 26 days, and almost 350 million e-mail messages, only 28 sales resulted -- a conversion rate of well under 0.00001%. Of these, all but one were for male-enhancement products and the average purchase price was close to $100. Taken together, these conversions would have resulted in revenues of $2,731.88 -- a bit over $100 a day for the measurement period or $140 per day for periods when the campaign was active. However, our study interposed on only a small fraction of the overall Storm network -- we estimate roughly 1.5 percent based on the fraction of worker bots we proxy. Thus, the total daily revenue attributable to Storm's pharmacy campaign is likely closer to $7000 (or $9500 during periods of campaign activity). By the same logic, we estimate that Storm self-propagation campaigns can produce between 3500 and 8500 new bots per day.

Under the assumption that our measurements are representative over time (an admittedly dangerous assumption when dealing with such small samples), we can extrapolate that, were it sent continuously at the same rate, Storm-generated pharmaceutical spam would produce roughly 3.5 million dollars of revenue in a year. This number could be even higher if spam-advertised pharmacies experience repeat business. A bit less than "millions of dollars every day," but certainly a healthy enterprise.

Of course, the authors point out that it's dangerous to make these sorts of generalizations:

We would be the first to admit that these results represent a single data point and are not necessarily representative of spam as a whole. Different campaigns, using different tactics and marketing different products will undoubtedly produce different outcomes. Indeed, we caution strongly against researchers using the conversion rates we have measured for these Storm-based campaigns to justify assumptions in any other context.

Spam is all about economics. When sending junk mail costs a dollar in paper, list rental, and postage, a marketer needs a reasonable conversion rate to make the campaign worthwhile. When sending junk mail is almost free, a one in ten million conversion rate is acceptable.

News articles.

Fascinating:

Paul Kelly and colleagues at Loughborough University found that a disulfur dinitride (S2N2) polymer turned exposed fingerprints brown, as the polymer reaction was initiated from the near-undetectable remaining residues.

Traces of inkjet printer ink can also initiate the polymer. The detection limit is so low that details of a printed letter previously in an envelope could be read off the inside of the envelope after being exposed to S2N2.

"A one-covers-all versatile system like this has obvious potential," says Kelly.

"This work has demonstrated that it is possible to obtain fingerprints from surfaces that hitherto have been considered extremely difficult, if not impossible, to obtain," says Colin Lewis, scientific advisor at the UK Ministry of Defence. "The method proposed has shown that this system could well provide capabilities which could significantly enhance the tools available to forensic scientists in the future."

I haven't seen the paper yet.

EDITED TO ADD (11/11): A really good article, and the actual paper.

Aspidistra was a World War II man-in-the-middle attack. The vulnerability that made it possible was that German broadcast stations were mostly broadcasting the same content from a central source; but during air raids, transmitters in the target area were switched off to prevent them being used for radio direction-finding of the target.

The exploit involved the very powerful (500KW) Aspidistra transmitter, coupled to a directional antenna farm. With that power, they could make it sound like a local station in the target area.

With a staff of fake announcers, a fake German band, and recordings of recent speeches from high-ranking Nazis, they would smoothly switch from merely relaying the German network to emulating it with their own staff. They could then make modifications to news broadcasts, occasionally creating panic and confusion.

German transmitters were switched off during air raids, to prevent them from being used as navigational aids for bombers. But many were connected into a network and broadcast the same content. When a targeted transmitter switched off, Aspidistra began transmitting on their original frequency, initially retransmitting the German network broadcast as received from a still-active station. As a deception, false content and pro-Allied propaganda would be inserted into the broadcast. The first such "intrusion" was carried out on March 25, 1945, as shown in the operations order at the right.

On March 30, 1945, "Aspidistra" intruded into the Berlin and Hamburg frequencies warning that the Allies were trying to spread confusion by sending false telephone messages from occupied towns to unoccupied towns. On April 8, 1945, "Aspidistra" intruded into the Hamburg and Leipzig channels to warn of forged banknotes in circulation. On April 9, 1945, there were announcements encouraging people to evacuate to seven bomb-free zones in central and southern Germany. All these announcements were false.

The German radio network tried announcing "The enemy is broadcasting counterfeit instructions on our frequencies. Do not be misled by them. Here is an official announcement of the Reich authority." The Aspidistra station made similar announcements, to cause confusion and make the official messages ineffective.

Nice.

First terrorists, then trash cans:

More than half of town halls admit using anti-terror laws to spy on families suspected of putting their rubbish out on the wrong day.

Their tactics include putting secret cameras in tin cans, on lamp posts and even in the homes of 'friendly' residents.

The local authorities admitted that one of their main aims was to catch householders who put their bins out early.

The Indian police are having trouble with SIM card cloning:

Police had no idea that one SIM card could be used simultaneously from two handsets before the detention of Nazir Ahmed for interrogation. Nazir was picked up from Morigaon after an SMS from his mobile number in the name of ISF-IM claimed responsibility for Thursday's blasts in Assam.

Nazir had a Reliance connection and an Eve handset. Each handset of this particular model has a unique International Mobile Equipment Identity (IMEI) number. Cops found that two IMEI numbers were using the same SIM. Accordingly there were two record sheets of calls and SMSes from Nazir's mobile number. The record of the SMS to the media was found in only one sheet, which forced police to believe that Nazir's SIM might have been cloned and someone else was using the duplicate card, with or without the owner's knowledge.

"We stumbled upon this technological surprise that Nazir Ahmed's SIM card was used in two handsets," Assam IG (Law and Order) Bhaskarjyoti Mahanta said.

So far, not that interesting. There are lots of vulnerabilities in technological systems, and it's generally a race between the good guys and the bad guys to see who finds them first. It's the last sentence of this article that's significant:

The experts said no one has actually done any research on SIM card cloning because the activity is illegal in the country.

If the good guys can't even participate, the bad guys will always win.

Really interesting post by Orin Kerr on whether, by taking hash values of someone's hard drive, the police conducted a "search":

District Court Holds that Running Hash Values on Computer Is A Search: The case is United States v. Crist, 2008 WL 4682806 (M.D.Pa. October 22 2008) (Kane, C.J.). It's a child pornography case involving a warrantless search that raises a very interesting and important question of first impression: Is running a hash a Fourth Amendment search? (For background on what a "hash" is and why it matters, see here).

First, the facts. Crist is behind on his rent payments, and his landlord starts to evict him by hiring Sell to remove Crist's belongings and throw them away. Sell comes a cross Crist's computer, and he hands over the computer to his friend Hipple who he knows is looking for a computer. Hipple starts to look through the files, and he comes across child pornography: Hipple freaks out and calls the police. The police then conduct a warrantless forensic examination of the computer:

In the forensic examination, Agent Buckwash used the following procedure. First, Agent Buckwash created an "MD5 hash value" of Crist's hard drive. An MD5 hash value is a unique alphanumeric representation of the data, a sort of "fingerprint" or "digital DNA." When creating the hash value, Agent Buckwash used a "software write protect" in order to ensure that "nothing can be written to that hard drive." Supp. Tr. 88. Next, he ran a virus scan, during which he identified three relatively innocuous viruses. After that, he created an "image," or exact copy, of all the data on Crist's hard drive.

Agent Buckwash then opened up the image (not the actual hard drive) in a software program called EnCase, which is the principal tool in the analysis. He explained that EnCase does not access the hard drive in the traditional manner, i.e., through the computer's operating system. Rather, EnCase "reads the hard drive itself." Supp. Tr. 102. In other words, it reads every file-bit by bit, cluster by cluster-and creates a index of the files contained on the hard drive. EnCase can, therefore, bypass user-defined passwords, "break down complex file structures for examination," and recover "deleted" files as long as those files have not been written over. Supp. Tr. 102-03.

Once in EnCase, Agent Buckwash ran a "hash value and signature analysis on all of the files on the hard drive." Supp. Tr. 89. In doing so, he was able to "ingerprint" each file in the computer. Once he generated hash values of the files, he compared those hash values to the hash values of files that are known or suspected to contain child pornography. Agent Buckwash discovered five videos containing known child pornography. Attachment 5. He discovered 171 videos containing suspected child pornography.

One of the interesting questions here is whether the search that resulted was within the scope of Hipple's private search; different courts have approached this question differently. But for now the most interesting question is whether running the hash was a Fourth Amendment search. The Court concluded that it was, and that the evidence of child pornography discovered had to be suppressed:

The Government argues that no search occurred in running the EnCase program because the agents "didn't look at any files, they simply accessed the computer." 2d Supp. Tr. 16. The Court rejects this view and finds that the "running of hash values" is a search protected by the Fourth Amendment.

Computers are composed of many compartments, among them a "hard drive," which in turn is composed of many "platters," or disks. To derive the hash values of Crist's computer, the Government physically removed the hard drive from the computer, created a duplicate image of the hard drive without physically invading it, and applied the EnCase program to each compartment, disk, file, folder, and bit.2d Supp. Tr. 18-19. By subjecting the entire computer to a hash value analysis-every file, internet history, picture, and "buddy list" became available for Government review. Such examination constitutes a search.

I think this is generally a correct result: See my article Searches and Seizures in a Digital World, 119 Harv. L. Rev. 531 (2005), for the details. Still, given the lack of analysis here it's somewhat hard to know what to make of the decision. Which stage was the search — the creating the duplicate? The running of the hash? It's not really clear. I don't think it matters very much to this case, because the agent who got the positive hit on the hashes didn't then get a warrant. Instead, he immediately switched over to the EnCase "gallery view" function to see the images, which seems to be to be undoudtedly a search. Still, it's a really interesting question.

People have been sending me this paper that "proves" that P != NP. These sorts of papers make the rounds regularly, and my advice is to not pay attention to any of them. G.J. Woeginger keeps a list of these papers -- he has 43 so far -- and points out:

The following paragraphs list many papers that try to contribute to the P-versus-NP question. Among all these papers, there is only a single paper that has appeared in a peer-reviewed journal, that has thoroughly been verified by the experts in the area, and whose correctness is accepted by the general research community: The paper by Mihalis Yannakakis. (And this paper does not settle the P-versus-NP question, but "just" shows that a certain approach to settling this question will never work out.)

Of course, there's a million-dollar prize for resolving the question -- so expect the flawed proofs to continue.

Impressive.

EDITED TO ADD (11/3): Here's the paper.

Two items, one short and one long.

The short one: "A Look at Terrorist Behavior: How They Prepare, Where They Strike," by Brent Smith, National Institute of Justice Journal, No. 260, 2008.

The long one: How Terrorist Groups End: Lessons for Countering al Qa'ida, by Seth G. Jones and Martin C. Libicki, RAND Corporation, 2008.

Video in Japanese.

And an (unrelated) cartoon.