Archives for 2004

In the recent hooha about CBS and the forged National Guard memos, one important issue has somehow been overlooked – the impact of the memo discussion on future forgery. There can be no doubt that all the talk about proportional typefaces, superscripts, and kerning will prove instructive to would-be amateur forgers, who will know not to repeat the mistakes of the CBS memos’ forger. Who knows, some amateur forgers may even figure out that if you want a document to look like it came from a 1970s Selectric typewriter, you should type it on a 1970s Selectric typewriter. The discussion, in other words, provides a kind of roadmap for would-be forgers.

This kind of tradeoff, between open discussion and future security worries, is common with information security issues – and this is a infosecurity issue, since it has to do with the authenticity of records. Any discussion of the pros and cons of a particular security system or artifact will inevitably reveal information useful to some hypothetical bad guy.

Nobody would dream of silencing the CBS memos’ critics because of this; and CBS would have been a laughingstock had it tried to shut down the discussion by asserting future forgery fears. But in more traditional infosecurity applications, one hears such arguments all the time, especially from the companies that, like CBS, face embarrassment if the facts are disclosed.

What’s true with CBS is true elsewhere in the security world. Disclosure teaches the public the truth about the situation at hand (in this case the memos), a benefit that shouldn’t be minimized. Even more important, disclosure deters future sloppiness – you can bet that CBS and others will be much more careful in the future. (You might think that the industry should police itself so that such deterrents aren’t necessary; but experience teaches otherwise.)

My sense is that it’s only the remote and mysterious nature, for most people, of cybersecurity that allows the anti-disclosure arguments to get traction. If people thought about most cybersecurity problems in the same way they think about the CBS memos, the cybersecurity disclosure argument would be much healthier.

Responding to my entry yesterday about pokerbots, Jordan Lampe emails a report from the world of backgammon. Backgammon bots play at least as well as the best human players, and backgammon is often played for money, so the temptation to use bots in online play is definitely there.

Most people seem to be wary of this practice, and the following
countermeasures have been developed (not necessarily exclusive or all
used by the same person)

1) Don’t play for money; only play for fun
2) Play money only against people you know [well]
3) Against somebody who takes a long time after every move, you are
suspicious that they are plugging their moves into computers
4) At the end of the game, you can analyze your game with one of the
computer programs. It turns out that all the computers rate each
other’s play very highly, with an error rate of 0-1.5 “millipoints” per
move. If you get a rate of exactly 0 you can be dead certain they are
using the same computer program. Computers rate the best humans in the
world in the 3-4 range. In any case, if your opponent is using a
computer program to decide all his moves it is fairly easy to tell after
only a few games, and then avoid playing with that player any more.
5) Some players take the attitude, “if I lose, at least I’ll have
learned something” and therefore ignore if they are playing bots
6) Using a bot to help you win is, well, boring, and so it doesn’t
happen that much anyway

Having played a lot of poker and backgammon in my day, I suspect that distinguishing human play from computer play would be harder in poker than it is in backgammon. For one thing, in backgammon you always know what information your opponent had in choosing a certain move (both players have the same information at all times); but in poker you may never know what your opponent knew or believed at a particular point in time. Also, a good poker player is always trying to frustrate opponents’ attempts to build mental models of his decision processes; this type of misdirection, which a good bot will emulate by using randomized algorithms, will make it harder to distinguish similar styles of play.

Jordan identifies another factor that several poker players mentioned as well: the fact that most gambling income is made by separating weak players from their money. As long as there are enough “fish”, all of the sharks, whether human or not, will feast. When the stakes get high, the fish will be driven out; but at low stakes, good human players may still make money.