Thoughts from Microsoft Research

By Larry Seltzer  |  Posted 2004-03-21 Print this article Print

I asked Microsoft about the problem I mentioned above with respect to hijacked open-proxy systems, and I got this response from Ted Wobber and Cynthia Dwork, both senior researchers at Microsoft Research, Silicon Valley:
    "Hijacking of end-user systems poses today, and always will pose, problems for all sorts of anti-spam solutions (among other things). Adding computational puzzle-solving will make intrusion much more noticeable, so users will 1) notice and 2) have added incentive to protect their computers. In addition, computational puzzle-solving will severely reduce the rate at which spammers can send spam from hijacked machines. Thus, even if spammers manage to capture an order of magnitude (or two) more machines than they have today, the Internet on the whole should still see less spam."
Both are good points, but are they good enough?. Im pretty sure that most users infected long-term with worms like SoBig are oblivious to such problems and will take their compute-power beating with a virtual "Thank you sir, may I have another." But Wobber and Dwork are right when they say that if the postage is high enough, these systems wont be able to send anywhere near as much spam.

But whats the point of all this when authentication systems are far easier to implement? Unlike Penny Black, they dont require any changes to the user mail software. Lets assume that authentication systems do authenticate properly. They still leave the possibility of spammers sending spam from authenticated systems without all the spoofing they currently use. Authentication advocates (thats me, folks) generally presume that some such spam would get through, but that reputation systems would quickly pick up on authenticated spammer domains and get the word out on them. Penny Black could then be a useful alternative to stop such spam from being practical.

Im a big fan of authentication, in large part because it requires no changes at all in the client software, as Penny Black does. So even though Penny Black makes authentication work better, I cant get too excited about it. It would be hard to get all the server changes invoked to make authentication work. Getting Penny Black to work requires a brain transplant on the whole e-mail infrastructure. Whatever its merit, its right up there in likelihood with pigs flying, Castro declaring free elections and a Cubs-Red Sox World Series.

Security Center Editor Larry Seltzer has worked in and written about the computer industry since 1983.

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Larry Seltzer has been writing software for and English about computers ever since—,much to his own amazement—,he graduated from the University of Pennsylvania in 1983.

He was one of the authors of NPL and NPL-R, fourth-generation languages for microcomputers by the now-defunct DeskTop Software Corporation. (Larry is sad to find absolutely no hits on any of these +products on Google.) His work at Desktop Software included programming the UCSD p-System, a virtual machine-based operating system with portable binaries that pre-dated Java by more than 10 years.

For several years, he wrote corporate software for Mathematica Policy Research (they're still in business!) and Chase Econometrics (not so lucky) before being forcibly thrown into the consulting market. He bummed around the Philadelphia consulting and contract-programming scenes for a year or two before taking a job at NSTL (National Software Testing Labs) developing product tests and managing contract testing for the computer industry, governments and publication.

In 1991 Larry moved to Massachusetts to become Technical Director of PC Week Labs (now eWeek Labs). He moved within Ziff Davis to New York in 1994 to run testing at Windows Sources. In 1995, he became Technical Director for Internet product testing at PC Magazine and stayed there till 1998.

Since then, he has been writing for numerous other publications, including Fortune Small Business, Windows 2000 Magazine (now Windows and .NET Magazine), ZDNet and Sam Whitmore's Media Survey.

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