
Death Note Anonymity: L, Anonymity and Eluding Entropy - rfreytag
http://www.gwern.net/Death%20Note%20Anonymity
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hibikir
Death Note would have been an extremely boring comic if Light had been smart
or a bit ruthless. Given how easy disinformation is with a death note, it'd
not be hard to hide the fact that he existed for years, and even after someone
figured it out, to make it almost impossible to figure out his location.
Nobody is getting bits of information about you if they don't know you exist.

So what we get in Death Note is a calamitous lead character that has to make
middle schooler mistakes, that then suddenly develops some smarts: It's the
only way to make the net grow close early on, but then withstand a few more
books. But even with the whole second kira twist and all of that, it's very
hard to make the story coherent, and kira not get caught very quickly after
making the mistakes that are mandatory to make the story any fun. Ultimately,
Ohba has to rely on making L also act in pretty suboptimal ways, just to make
the first arc of the story last long.

Which brings us to how Death Note is a good example of why it's so hard to
make realistic crime stories: It's very difficult to make a story long enough
to not be trivial, and yet have the criminal get caught in the end: It's far
easier to make a very good criminal or a hapless one than to make one that
will move the story along at a good pace.

~~~
veridies
They actually address this in the comic / show: Light wants people to know he
exists. He wants to be seen as a god with the power to smite evildoers, which
requires being known to exist. Simply killing criminals covertly wouldn't
accomplish his goals.

~~~
dragontamer
Indeed. Furthermore, he highlights the killing of Ray Penbar's wife as a
"mistake". However, Ray Penbar's wife was literally about to tell L that Light
can kill using methods aside from heart attacks.

The fact of the matter remained: when Light wanted to "hide" a death from the
Police, he'd use a different method. (Episode 5: Kill by Traffic Accident).

The fact of the matter is, if Ray Penbar's wife actually got the information
out to L, then Light would have lost right there and then. He was forced to
kill her as soon as she was discovered.

If anything, his mistake was killing the FBI team through Ray Penbar in the
episodes earlier. Ray Penbar wasn't suspicious of Light... but when Ray Penbar
died then the entire L investigation focused on him.

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steckerbrett
Probably mostly towards the end of getting a good story, two of the behaviors
mentioned in this article as erroneous are somewhat intentional (though all
the effects aren't). Light specifically mentions that he is making his deaths
visible because he wants people to know that there is someone behind it,
playing into the idea that he has gained godlike powers and will use them to
change the world. He also goes out of his way to bait L to some degree in an
attempt to eliminate him, believing L to be the only true obstacle in the way
of achieving his end goal. With hindsight this is obviously the wrong move to
make (he gave away a lot of information for no good reason), but you can see
why someone faced with an invisible enemy might feel like drawing out their
opponent is a good idea.

All that said attempting to anonymize his targets probably wouldn't have done
him that much good anyway. As a Japanese person his sources of news and
information would be at least on some level biased towards hearing about
events which have some connection to Japan. Even if he was able to overcome
that through the internet, people have a very noticeable habit of treating
things physically closer to them as being more real than something on the
other side of the world. Adding entropy within a limited information aperture
only gets you so fat, I'm pretty sure he would have still had information
leaking just through that lone.

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joshbaptiste
Ah "Death Note" one of my Anime favorites of all time, I'm not an Anime zealot
but Death Note was my gateway drug into other types of Anime that weren't only
action based, truly brilliant.

~~~
autarch
If you like Death Note I highly recommend Monster, which is a similar not-type
anime with a focus on psychology and philosophy. It's one of the most
brilliant pieces of writing I've ever experienced.

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MichaelGG
I find it hard to drive home how much info people leak. Just the cultural
references you make, cross referenced with Kindle purchase history...

But as touched on, the real question is how well does disinformation work
against LE? We see all sorts of dumb reveals in court documents. A single line
like "yeah I spent 30 days in jail for pot last summer" really narrows it
down. But how far will it throw LE off if such a slip is false? Are they
actively trying to determine this kinda thing? Without knowing how many
investigations simply fail, I suppose it's hard to know.

I guess the best indicators are the long-standing evasions we know of, such as
the FBI agents that the KGB turned.

The other take-home lesson is to use high-latency communication. In the
lulzsec investigations, agents monitored when Tor was on in the suspect's
apartment, correlated to when the handle was chatting. (OK he was probably
toast at that point anyways.) I'd also guess that doing batch communication
reduces the tendency to slip up. No small talk. Also no external interruptions
("sorry, power just went out for a minute") to mention.

~~~
steckerbrett
A mention isn't even necessary. Imagine being Light getting his source of
information from the internet, his ISP has a small incident with a lightning
storm and they lose connectivity completely for a few days while things get
sorted out. Involuntarily information has just been leaked irregardless of all
other protections, the deaths of criminals would have been disrupted. In this
situation you would ideally be working to some great latency of days or weak
to give a buffer of information. It's talked about in the first few episodes
that he works ahead in case of sickness, but it's not mentioned after that,
possibly because it means he can't use those events as cover for on the spot
murders (which would stand out from week old information based murders).

~~~
kaybe
Maybe it would have made sense to only use week-old information to begin with.

~~~
steckerbrett
Probably would have been a better idea. Only later in the Anime does he
actually need to do things quickly, all the rest really could have waited
weeks or even months. That said it wouldn't have made for very interesting
watching if he managed to have that much forward thinking all the time.

~~~
kaybe
Well, being a keyboard warrior is easy. ;)

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dvdfvo
The most implausible part seems to be that L is completely anonymous. He is
clearly operating with other people, therefore he leaves a trail of
information. Even if he is perfect at covering that up, people working with
him aren't.

Light could also use his powers to extort. Someone in the
police/media/politics must know who L is. Therefore it would be only a matter
of time until you hit a person that knows him. An alternate approach to this,
which is contrary to Light's beliefs, is to keep executing important people
until L is revealed, someone will reveal him eventually.

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qznc
If you are look for more fiction, which tries to be "realistic" or as I would
say "internally consistent", there is some community on reddit:
[https://www.reddit.com/r/rational/](https://www.reddit.com/r/rational/)

This is about "rational" fiction, which is well explained here:
[http://tvtropes.org/pmwiki/pmwiki.php/Main/RationalFic](http://tvtropes.org/pmwiki/pmwiki.php/Main/RationalFic)

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kijin
Anyone seeing this?
[https://i.imgur.com/WQMM3Tu.png](https://i.imgur.com/WQMM3Tu.png)

The page is unreadable for me. Firefox 38.0.1 on Windows 7. Disabling AdBlock
doesn't seem to help.

~~~
yukinon
Firefox 38.0.1, Windows 7 here. Works fine for me.

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scythe
"differential privacy is impossible" \-- might we have argued after the
failure of Enigma in World War II that unbreakable encryption was impossible?
Absence of evidence is not very reliable evidence of absence.

~~~
gwern
> that unbreakable encryption was impossible?

Isn't that still an open question? We have Shor's algorithm which disposes of
a bunch of things on its own, and the existence of one-way functions at all
remains an assumption rather than a known fact.

~~~
pbsd
Information-theoretically secure encryption and authentication do exist, so in
a sense unbreakable (authenticated) encryption is a fact. Outside of that, the
existence of OWFs is indeed an assumption, but I doubt anyone's losing sleep
over it.

The original argument didn't make sense to begin with: the SIGABA rotor
machines used by the US during WW2 were never known to have been broken during
actual use, so the only reasonable conclusion about cryptography to draw at
the time was that Enigma was simply a poor instance of it.

