Death Note: L, Anonymity & Eluding Entropy
gwern.net
gwern.net
As a side note, has anyone else considered the possibility that it's entirely possible that Light could have simply set up a server which would schedule his victims' deaths for a certain randomised time, then at that time pull up an image of them on X and print their name on one page of the death note which was set up to be indefinitely recycled within the same printer?
At that point it'd have been trivial for him to set up a simple password-protected REST interface which would accept POST requests of victims' names/pictures, and he could have even done all his future recruiting through Tor without taking the risk of using physical mail (and eventually facilitating the recruitment of a local "Kira" in every country, possibly vetting through social media comment histories in a similar fashion to the way he evaluated Mikami).
This setup wouldn't necessarily have been possible, but the wording of the Death Note looks like it might have allowed for it (contingent on how strictly it defined "mind"). At the very least, printing through electronic media would have been worth an experiment.
Assuming the server were reasonably secure, and he'd taken appropriate steps to scale as time passed, the very fact of all that ink on one page would have made it completely illegible, and thus inconclusive evidence. Then, he could have just performed any Kira actions from a virtual machine with an encrypted filesystem, eventually ceasing any direct killings as his army increased in size. It would have scaled beautifully, and he'd have been almost perfectly anonymous.
To put the icing on the cake, if he didn't want to put in so much grunt work, he could have simply configured his server to automatically hook into every well-maintained reputable public listing of convicted violent criminals (as well as listings like the website of America's Most Wanted) and then forgotten about the whole thing. And hell, if the whole thing is automated, why not just put in a line of code that marks each death as being at the hands of the most likely intelligence agency? It would have achieved the same chilling effect ("OMG THE CIA IS KILLING EVERY CRIMINAL IN THE WORLD NOW!"), and thus the same goal, without even realistically risking his own livelihood.
Like I said, this depends on a bit of a loose definition of "mind", so it might not have worked at all.
Here is the exact wording of the rule in question: "This note will not take effect unless the writer has the person’s face in their mind when writing his/her name. Therefore, people sharing the same name will not be affected."
It specifically appeals to the (somewhat hazy) concept of mind, which would imply the prerequisite of some sort of sentience. However, the rules are not absolute, but rather based on Ryuk's imperfect interpretation (Ryuk didn't know a priori how certain experiments would turn out, like writing causes of death before names with the FBI agents); thus, the use of "mind" itself isn't so important, as it merely implies that Ryuk's experience is limited to sentient beings, which should be obvious.
In other words, there isn't any way to know whether a death note could be used in this way without testing it on a "real" death note (or having the authors write canonical material on it).
Solving for maxima in the Law of Universal Perversity should do it.
The story emphasises that Deathnotes are fairly literal, and that if you try to push it you'll just get a heart attack death.
I'm not sure why it's on hacker news-- so I called them tv shows and comic books to offend the otaku.
The part about the time of day was found out long after L had narrowed things down to a small region of Japan by provoking Light into killing someone who appeared on a "worldwide" broadcast that was actually only broadcast in Light's prefecture. The time of day part was actually used to hypothesize that Light was a student, whereupon the pattern changed to show people killed every hour of the day. And L saw through that by assuming (correctly) that Light had access to police data. It seemed like he was always watching Light's reactions to his moves, rather than the moves themselves.
Probably one of the most clever traps of all was after they met in person, when L was able to trap Light by getting evidence that Light knew something he should have no way of knowing at all by means of false evidence. He played it off as Light being too dumb to figure out the riddle, but the only reason he couldn't solve it was because he thought the answer was impossible (and he shouldn't have known that).
But it never really turned out to matter, as you say. L was able to notice that weird case where the evil guy who had taken school children hostage died of a mysteriously timed heart attack and piece a lot of things together.
Actually, though, that broadcast was probably one of the most important puzzle pieces. He was able to prove that Light could kill remotely with nothing but a face & name, having cut a special deal with a criminal and kept the guy under special observation the whole time. Light was very careless there.
Do the bits of entropy add on, or does it not matter at all?
But once #2 and #3 become equally active, now any evidence like that serves to narrow down the propositions 'any of #1, #2, #3 are in Japan', so if someone asked you what's the odds that #2 lives in Japan, you would only have 1/3 the evidence you did before - because any kill linked to Japan would only have 1/3 chance of having been #2. If a kill is made using information from a rural Iowan newspaper with circulation of 100, well, all you know is that any of 1/2/3 had access to it (and maybe all 3!). And so on.
(In bit terms, if there were 4 Death Note users, then any observation has 1/4 the power it did, or 1/2^2; similarly, if there were 16 users, or 32 users... Once you established someone was a Death Note user you would still need to do that many more bits of work to figure out which Death Note user you want.)
I'm getting a lot of [Math Processing Errors] when I view your article: http://imgur.com/PSeMX I haven't looked at the source to see what was going on, so it might be that I'm blocking flash or something.
Otherwise, it was great! :) Thanks for a fun read!
I think technology could provide such a future, for example something like those tiny poison drones in the movie Dune.
Or maybe it will be possible to genetically engineer a virus to just kill one specific person - kind of like Stuxnet was targeted at one specific factory...