Comments on: First we assume a circular CD

By: Shtetl-Optimized » Blog Archive » How to rig an election

Shtetl-Optimized » Blog Archive » How to rig an election — Thu, 21 Dec 2006 18:43:46 +0000

[...] My friend Alex Halderman is now after bigger fish than copy-”protected” music CD’s. Watch this video, in which he, Ed Felten, and Ariel Feldman demonstrate how to rig a Diebold voting machine (and also watch Alex show off his lock-picking skills). Reading the group’s paper, one becomes painfully aware of a yawning cultural divide between nerds and the rest of the world. Within the nerd universe, that voting machines need to have a verifiable paper trail, that they need to be open to inspection by researchers, etc., are points so obvious as to be scarcely worth stating. If a company (Diebold) refuses to take these most trivial of precautions, then even without a demonstration of the sort Alex et al. provide, the presumption must be that their machines are insecure. Now Alex et al. are trying to take what’s obvious to nerds into a universe — local election boards, the courts, etc. — that operates by entirely different rules. Within this other universe, the burden is not on Diebold to prove its voting machines are secure; it’s on Alex et al. to prove they’re insecure. And even if they do prove they’re insecure — well, if it weren’t for those pesky researchers telling the bad guys how to cheat, what would we have to worry about? [...]

By: Greg Kuperberg

Greg Kuperberg — Thu, 17 Nov 2005 21:02:00 +0000

It partly depends on what you mean by a classical state. An indefinite classical state cannot be copied any more than a quantum state can.

Part of the point is that in quantum theory, all states are indefinite. Pure states are the most definite, but they are still indefinite.

By: Scott

Scott — Thu, 17 Nov 2005 05:09:00 +0000

Anonymous: The “no-cloning theorem” says that there’s no way to copy an unknown quantum state (i.e. if you try to duplicate the state, you’ll destroy its quantum coherence). Indeed, a pure quantum state can be copied if, and only if, it belongs to a known orthogonal basis. Fortunately, the set of n-bit strings (or in other words, computational basis states) constitutes just such a basis.

All of that was just a fancy, highfalutin’ way of saying that classical information (being classical) can be copied!

By: Anonymous

Anonymous — Thu, 17 Nov 2005 01:03:00 +0000

Can you tell us a bit more about the implication made in this statement:

“For me, it follows from the fact that the set of n-bit strings constitutes an orthogonal basis for Hilbert space.”

This is yet another instance where I know ever single word (and jargons) in a sentence but I don’t know what the sentence actually means.

By: Scott

Scott — Wed, 16 Nov 2005 16:25:00 +0000

Eldar: First4Internet and SunnComm both have new DRM software, with different “innovations.” The First4Internet one does seem worse security-wise. But the SunnComm one is easier to explain, and funnier!

By: Eldar

Eldar — Wed, 16 Nov 2005 13:38:00 +0000

To set the record straight, the new DRM software is by First4Internet, not SunnComm. It’s crown jewel “feature” is a generic rootkit (read that “trojan”) that makes your system unable to see or delete certain files on the disk. In the spirit of free commerce there seems to be already 3rd party malware that taps this crippling of your system. A bit little and too late, Sony is now making steps to contain the damage, as this one has the potential to be the one that backfires at them.

One more thing for the irony – there are allegations that the DRM software has copyright violations in its own code, as it incoporates pieces of Free Software projects whose license does not allow this mode of distribution.

By the way, I should state that I am not in the inner loop myself – the above is from what I read over the net.

By: Luca

Luca — Wed, 16 Nov 2005 10:05:00 +0000

Erdos had this story of how he “independently discovered” negative numbers when he was four.

By: Scott

Scott — Wed, 16 Nov 2005 08:37:00 +0000

“I wonder how often do kids reinvent things?”

My guess: far more often than most people think! The best researcher would be someone with the knowledge, confidence, and intellectual honesty that come from decades of experience, but the brain of an 11-year-old.

PS. Of course, Heisenberg’s principle deals with the product of uncertainties of a pair of noncommuting observables, not with the disturbance to any one of them caused by measurement.

By: Anonymous

Anonymous — Wed, 16 Nov 2005 08:17:00 +0000

Ah…well I would not have been able to understand the calculus even if I had access to the book since I didn’t even know about algebra in the 7th grade.

I wonder how often do kids reinvent things? When I was a child it seemed obvious to me that if you tried to “look at” or measure elementary particles that you would change their position/momentum simply by interacting with them. I remember my disappointment when I found out that Heisenberg had already discovered the Uncertainty Principle!

By: Scott

Scott — Wed, 16 Nov 2005 07:55:00 +0000

Anonymous: The summer between 6th and 7th grades, my brother had a babysitter who’d taken calculus in college. She gave me her textbook, and I read as much of it as I could.

A few years before that, I’d invented a new field called “graph analysis,” which I was sure would revolutionize the world. Given a sequence of numbers, the idea was to find the “rate of change,” “rate of change of the rate of change,” etc. by taking successive differences between entries, like so:

6 4 7 8 1
-2 3 1 -7
5 -2 -8
-7 -6

You could also reverse that operation by taking cumulative sums. It was a big disappointment to learn that Newton and Leibniz had already done this for continuous functions, which is the nontrivial part!

Anyway, you’re lucky to have had a good programming instructor as a kid. That class sounds awesome.