Slashback: Passports, Microscopes, IQ Points

Slashback tonight with updates and clarifications on recent Slashdot stories (and story arcs), including a downright Operatic end to Jon S. von Tetzchner's cross-oceanic attempt (or was that just in fun?), the status of post-death email privacy, minimizing the dangers of RFID passports, and more - read on for the details.

Actually, it's taking tests that reduces IQ. The guys at Mind Hacks have dissected the widely reported story that 'email destroys the mind faster than marijuana' [Posted on Slashdot a few days ago -- T.] and found that it is more spin than science. The results show simply that people do worse at IQ tests when distracted, although Hewlett-Packard are not releasing details of the experiment, so others cannot even evaluate if the research is sound. The use of psychobabble for marketing marches on.

One day this will all be commemorated as ... an opera. GreyPoopon writes "It looks like Jon's attempt at swimming the Atlantic has ended in early failure. Taking the blame once again is is PR Manager, Eskil Sivertsen. The raft he was using was somehow punctured this morning, and Jon had to abondon his trek to perform a heroic rescue. Perhaps someone should take on the task of sending our downtrodden adventurer a cup of Mom's hot chocolate."

PCP theorem simplified, still way over my head. Stridar writes "Sanjeev Arora's proof of the PCP theorem was a great acheivement. This theorem, a reduction of NP to PCP, allowed for many striking results on the difficulty of finding approximate solutions to NP-Hard problems. However, his original proof is long and technical, focusing on the arithmetization of booelan formulas. It has long been an open problem to simplify this result. Now Irit Dinur , a mathematician at the Hebrew University, has given a purely combinatorial proof of the PCP theorem, in her exciting paper "The PCP Theorem by Gap Amplification" ."

I think several other things end at death, too. microbee writes "The Register reports that Yahoo has complied with a court order to give a dead soldier's email account to his parents. It's not clear to me from the news whether they got direct access to the actual mail box, or just hard copy of those emails. If the former, it's a bit funny to read "the family complain they have only got emails received by Justin, not those he wrote." People have to wonder whether their privacy ends at death."

Haven't they ever seen The Killing Fields? valdean writes "Following up on past Slashdot stories, Wired News reports that the State Department is now considering adding a password to the new RFID passports, in response to 'criticism from computer security professionals and civil libertarians.' According to the article, 'The data... would be locked and unavailable to any reader that doesn't know a secret key or password to unlock the data. To obtain the key, a passport officer would need to physically scan the machine-readable text that's printed on the passport page beneath the photo... The reader would then hash the data to create a unique key that could be used to authenticate the reader and unlock the data on the RFID chip.'"

Anything with LEDs in it makes me happy. HunterD writes "Apparently a company called DigitalBlue purchased the rights to the Intel Play series, which included the Intel QX3 microscope. Well, DigitalBlue has released an upgrade called the QX5 that features an Ultrabright LED, a better camera, and a number of other upgrades."

Comments

PCP Theorem

[BandwidthHog]

If, after checking your email while doing bonghits you can still count to one, proving theorems on PCP oughta do the trick.

Yes a novel solution...

[t_allardyce]

Or how about just NOT using RFID in passports and instead using tried and tested chips or strips? And no, not having to replace worn out passports is does not take priority over privacy and security, most people don't use their passports more than a dozen times a year anyway, I use my debit card every day and the chip is fine, theres no excuse to use RFID.

The PCP Theorem

[cpeikert]

The PCP theorem is a beautiful piece of computer science and mathematics. What's it good for? Well, for starters:

• One can use it to show that not only are some problems very hard to get exact answers to, they are very hard to even get approximate answers to! In the most extreme case, it's hard to tell whether a graph has an enormous clique (taking up almost all the vertices), or just a very small one.
• PCPs can be used to build very low-communication zero-knowledge proofs. So you can prove a mathematical statement to someone, using much less communication than it takes to even write down that statement, and giving her no idea why the statement is true, even though she will be absolutely convinced that it really is true!
• PCPs can also be used to write down a (long) proof of a mathematical theorem, so that to check the theorem only requires you to look in a few random places. If the theorem is false, you'll detect it, otherwise you'll be convinced that it's true. It's as if there was a huge book of mathematics, and you opened to a random page, read a few characters, and said, "yep, it's definitely all true."

In short: amazing!

Re:The PCP Theorem

[Nitish]

Well, you don't need to feel bad about not understanding the PCP theorem. It's a difficult concept to grasp. For example, you could be an extremely intelligent and motivated high school student who can't "get it" even if you try, because you just haven't studied all the pre-requisite material you need. Though perhaps you can't go to the PCP theorem from where you are now, you might be able to understand it once you have all the background knowledge.

The original poster described the PCP theorem well, but it might not make a lot of sense to people who haven't studied algorithms or complexity theory. This might help:
A lot of problems people want to solve in practice are "optimization" problems. That is, given a problem, we want to find the optimum (minimum or maximum, as the case may be) solution. For example, if you have to travel to several cities, you might want to know the cost of the cheapest tour that visits all of them. Or you might want to know what the most efficient way of scheduling jobs on a machine is. These (and several other) problems, are what we call NP-Hard. That has a technical meaning, but in short, it takes a *really* long time (far more than is practical) to compute the best solutions for these problems. And so if you wanted a solution, instead of spending forever to find the best tour, you might settle for a tour that cost only 1% more, if you could find it quickly. Algorithms which do this are called approximation algorithms; they don't always find the best solution, but they approximate it - the solution they find is nearly as good... perhaps just a little more expensive or less inefficient.

Approximation algorithms are useful because people are often satisfied with solutions that are "good enough", even if not perfect. So for a hard problem, it's worth spending time trying to find a good approximate solution.

Enter the PCP theorem! You can use it to show that some problems can't even be approximately solved in a reasonable amount of time, and that's what the original poster was talking about.

Besides this, the theorem is important and loved because not only is it useful, it's non-obvious and beautiful

Re:The Passport Password

[BandwidthHog]

Time to buy a farraday cage for your passport...

Gives new meaning to the old expression "Keep it under your [tinfoil] hat."

I like the idea of Emails being made public

[Ciderx]

...after my death.

If you knew you were going to die soon, I'd have a sent mail list which would be great and populated with loads of fake emails that said things like:

"Look, Adriana. I don't care how many other Victoria's Secrets models you're going to bring, I'm NOT going to sleep with you. And, BTW, what you suggested is (a) a waste of whipped cream and (b) isn't that a rather large vegetable for something like that?"

and, of course

"Oh, I figured out how to cure cancer and the key to world peace. I'll email you in a few days with the details..."

Re:I like the idea of Emails being made public

[antifoidulus]

What about the people you exchanged email with? Email is not like a journal, there are at least 2 parties involved and the privacy of those people is equally as important of the privacy of the soldier. My solution would be that if the people with whom the deceased communicated with should decide whether or not they want to forward the email on to the parents.

Truly Operatic end?

[serutan]

Pretty obvious that this is a joke. I'm surprised nobody has commented on it yet. Check out the guy in the dinky raft, supposedly the support vessel. Classic.

"A local farmer spotted the drama from his kitchen window and took surprisingly sharp photos with a remarkably powerful telescopic lens."

And all the while he was milking a goat! Remarkable indeed!

Re:MJ?

[Ugodown]

It's a consensus that no brain cells are killed from the ingestion of marijuana, it will impare learning, but what do you expect when you're stoned? After a period of time of not using it, IQ levels and intelligence goes right back to normal levels. The only emperical evidence of brain damage comes from an experiment with monkeys where they were administered with 200x the normal amount. Check this out: http://www.marijuana.com/Exposing_08_1095.html it has sources

Re:MJ?

[stanleypane]

You have got to be joking, right? Lets start from the top:

- Prisons: Overcrowded as it is. Our local city lock-up in Baltimore doesn't even have the capacity to process possible *murder* suspects within the required 24 hours. Public defenders are getting people out of lockup EVERYDAY -- without charge -- because of this problem.

- Police: The last time a cop caught me with a joint, he told me to throw it out. The cops around here don't have the time to keep arresting kids for smoking pot. They have more serious problems to worry about.

- Judges: Don't know about your town, but in mine it may takes up to 6 months after being arrested before you even see a judge for a formal hearing. I don't think it is because of all the pot smokers.

- Marijuana dealers: I don't even know where to start with this one. I'll leave it alone.

That being said; I don't know if I think marijuana will be legalized in my lifetime, but I wouldn't be surprised if cops started treating it more and more like underaged drinking. Similar to, "OK, start dumpin 'em out, kid."

Linux QX3 drivers

[jonsmirl]

The CPiA webcam driver supports the QX3 on Linux.
CPiA webcam driver for Linux
Just turn on CONFIG_VIDEO_CPIA=m when you build your kernel. You can even use /proc to turn the microscope lights on and off.

CPiA is not made any more. Maybe the QX5 uses a similar webcam chip.

Old slashdot story about the QX3

Physically Scan

[jeffkjo1]

To obtain the key, a passport officer would need to physically scan the machine-readable text that's printed on the passport page beneath the photo

Ok, at this point, they're already scanning the passport, why not just put all the information on the magnetic strip, rather than waste money on an additional RFID chip?

Re:MJ?

[flink]

You left out the biggest one: seized assets of drug dealers. When someone gets convicted, federal laws allow all their drug-related assets (cars, bank accounts, houses, bling, etc.) to go to the state. This is a huge revenue stream for local law enforcement agencies and is probably the single largest unspoken reason why you won't see legalization anytime soon.