
The Prison Guard With a Gift for Cracking Gang Codes - shmageggy
http://nautil.us/blog/the-prison-guard-with-a-gift-for-cracking-gang-codes
======
smcl
"The messages will disparage other gangs in a backhanded way. In a Blood
letter, you’ll see that the letter C is usually crossed out or has a slash
through it out of disrespect for the Crips. And to praise themselves, they’ll
write a B with an up arrow."

It's so strange that there's these very serious gangs responsible for
traumatising large areas in US cities, yet they do massively petty things like
writing a "WE R KOOL" up-arrow beside a 'B' in their correspondence, and
crossing out a 'C' (if they're a Blood that is). I can't connect that juvenile
elementary school behaviour with gang violence and shootings, it seems so
contradictory.

~~~
thaumasiotes
Gang violence is the default state; it is the behavior that children will
naturally develop without being socialized (and return to, whether child or
adult, in the absence of authority).

You're observing that these gang members haven't been socialized out of
instinctive self-congratulation in their writing, or out of instinctive pack
behavior. I don't see the disconnect.

~~~
sneak
> (and return to, whether child or adult, in the absence of authority)

[citation needed]

~~~
shin_lao
Enough with the "citation needed". This isn't Wikipedia. People have the right
to express an opinion or don't have reference for everything they say.

How would you react if someone told you "citation needed" every time you make
a claim?

~~~
colanderman
I would learn to write "I think that" in front of things that are my opinions.

~~~
bronbron
That sounds repetitive and kind of annoying to read. It's usually obvious from
context what's opinion and what's not, and you can always ask for
clarification in those rarer instances. For example, it's pretty obvious the
OP is stating opinion.

You don't need to couch your opinions with "I think" or "It's my opinion
that". Have some conviction.

~~~
dspillett
_> Obvious to you. And me for that matter._

Obvious to you, and me for that matter, but obviously not obvious to everyone
or this sub-thread would not exist. Every one in this threat seems to be well
enough versed on English that a specific language barrier isn't an issue, but
there are probably people for whom English is a third or forth language: the
chance of them seeing as obvious everything that we pick out as obvious is
going to be lower than for those with more practise at the language.

 _> Have some conviction._

It is not about conviction, it is about accurately displaying the source and
potential veracity of the information being presented. I couch my opinions so
it doesn't look like I'm stating a commonly known fact instead of something
I've supposed. Of course where I'm pretty damn sure what I'm stating is
verifiable fact I'll not bother adding the extra words, but if you always
assume you are correct and write in a style that suggests such, then you may
be one of _those_ people!

Adding a few extra words to tell the reader this extra information about the
(potential) quality of the information you are about to impart is useful IMO.
Be as fine grained as you like too: somewhere between "I think that" and "I
know" is "It is my understanding that..." and so on.

~~~
bronbron
> Obvious to you, and me for that matter, but obviously not obvious to
> everyone or this sub-thread would not exist.

Why sacrifice conciseness to try and alleviate every misunderstanding?
Language is not a perfect communication tool - you'll talk yourself dizzy
trying to catch every edge case and possible interpretation.

> Every one in this threat seems to be well enough versed on English that a
> specific language barrier isn't an issue, but there are probably people for
> whom English is a third or forth language: the chance of them seeing as
> obvious everything that we pick out as obvious is going to be lower than for
> those with more practise at the language.

Great! So we're doing them a great service by giving them practice in reading
context.

> It is not about conviction, it is about accurately displaying the source and
> potential veracity of the information being presented.

Why? This isn't an academic discussion. If it looks like you're presenting
something as a fact and I think you're full of shit, I'll ask for a
clarification. Much like the poster did with the "[citation needed]". The OP's
message remains easy to read, and the sub-poster got the clarification they
were looking for.

> I couch my opinions so it doesn't look like I'm stating a commonly known
> fact instead of something I've supposed. Of course where I'm pretty damn
> sure what I'm stating is verifiable fact I'll not bother adding the extra
> words, but if you always assume you are correct and write in a style that
> suggests such, then you may be one of those people! Adding a few extra words
> to tell the reader this extra information about the (potential) quality of
> the information you are about to impart is useful IMO. Be as fine grained as
> you like too: somewhere between "I think that" and "I know" is "It is my
> understanding that..." and so on.

You're sacrificing conciseness for a very weak attempt at clarity. It's
incredibly tedious to read someone's opinion piece that says "It's my opinion
that vaccines are dangerous. I think that X. I believe that Y. I am of the
opinion that Z." It makes your message incredibly boring and unpersuasive.

Further, trying to turn this into an academic discussion brings into question
all the issues academic discussions engender. How reliable is your source?
Have you done the appropriate background reading? If you link a study that
says "vaccines are bad" but there are 300 other studies that say "vaccines are
good", are you really being objective?

And then of course we can get into some really stupid semantic debates, since
we're arguing about semantics anyway - what's the cutoff? If I say "the barn
is red", do you want spectroscopy results?

~~~
dspillett
_> Why sacrifice conciseness to try and alleviate every misunderstanding?_

Because this isn't twitter, there is no character/word limit so I consider
taking a little extra room to help the reader understand where I'm coming from
to be a good use of available comms bandwidth.

 _> > It is not about conviction, it is about accurately displaying the source
and potential veracity of the information being presented. > Why? This isn't
an academic discussion._

Because I prefer to be accurately understood in non-academic contexts too.

 _> If it looks like you're presenting something as a fact and I think you're
full of shit..._

My point is that if it looks like I'm presenting something as fact when that
was not my intention then I have failed to communicate properly, and you
unnecessarily think I'm full of shit.

 _> It's incredibly tedious to read_

Here you make the case for me. This could just be your opinion/feeling which
is fine, or it could be you stating that your opinion is the only correct one
and _everyone_ finds it tedious (or should). In the same way a little extra
wordage can avoid me looking to be full of shit, a little extra in the
sentence fragment would reduce the chance of you coming off as someone who is
overly self-important and assumes his thoughts are universal facts. Maybe
worrying about how I sound in this way is a neurotic issue...

 _> How reliable is your source?_

So to avoid problems with the reliability of my source, I should just not let
anyone know what the source is? Basically "trust me, I'm from the Internet, we
know these things"?

 _> If you link a study that says "vaccines are bad" but there are 300 other
studies that say "vaccines are good", are you really being objective?_

EXACTLY. I don;t see how pointing the that one study is _worse_ than just
stating the fact/opinion. With the link the reader can nip off and see if it
looks like what they would consider an acceptable source. With just that one
link and no others a semi-educated reader can make a judgement as to whether
my opinion is well enough informed to be trusted in any way. Heck, on a good
forum if you were to post a fact/opinion based on a single source (and state
the source) helpful people might suggest other sources you'd like to review,
and this extra information could be useful to other readers too. Of course
such discussions can get a bit flamey, but that is a human failing for another
discussion!

 _> If I say "the barn is red", do you want spectroscopy results?_

Not quite. You also need to provide the results of a scan of the back of your
eye, we need to know what signals your brain gets from the eye in response to
the wavelengths we consider to represent red - your optical nerve might be
wired up wrong. Of course these things can be taken too far, but I don't
consider making it clear that something is opinion (or believed to be a fact
but one based on limited research) rather than something I consider an
absolute incontrovertible truth not to be too far.

Yes, the reader needs to take some responsibility for not jumping to
conclusions based on the exact words we write, but the writer either needs to
make a little effort to not be misunderstood or accept that some will
completely misjudge where they are coming from (and of those two options I
generally choose the first, you presumably prefer the latter approach).

~~~
bronbron
>Because this isn't twitter, there is no character/word limit so I consider
taking a little extra room to help the reader understand where I'm coming from
to be a good use of available comms bandwidth.

Similarly stereotypical old people consider it to be a good use of time to
tell extremely rambling stories that explain the context of everything. Taking
the time to couch everything in "I think" or making dead sure everyone knows
it's "just your opinion" reminds me of Grandpa Simpson explaining that onions
were the style at the time - totally inconsequential information.

> Because I prefer to be accurately understood in non-academic contexts too.

Do you really worry that most people misunderstand you without those
qualifiers? Are you worried about every possible misinterpretation of your
sentences?

> My point is that if it looks like I'm presenting something as fact when that
> was not my intention then I have failed to communicate properly, and you
> unnecessarily think I'm full of shit.

Solved by a three word clarification on the off-chance someone misunderstands
you. Doesn't happen nearly as often as you think (please don't black swan me).

Opinions can be "full of shit" too. For example, I think people opposed to
same-sex marriage are full of shit. You're not really dodging that bullet just
by saying "Hey that's just my opinion!!!!"

> Here you make the case for me... Maybe worrying about how I sound in this
> way is a neurotic issue...

It sounds a little neurotic. It's pretty clear it's just my opinion - people
vary in their definition of "tedious". Some people enjoy knitting, I find it
tedious. If I say "knitting is tedious", one can assume that should not be
translated as "it is an objective fact that knitting is tedious."

> So to avoid problems with the reliability of my source, I should just not
> let anyone know what the source is? Basically "trust me, I'm from the
> Internet, we know these things"?

Depends on the situation. If you're saying the median income in Greece is
$32k/yr, then yeah, I want your source. If you're telling me, "Vaccines are
bad", it really doesn't matter what your source is.

Honestly ask yourself (this is rhetorical, by the way, because there's
naturally going to be a disconnect between typed and real answers): if a study
came out tomorrow saying "solid proof that children raised by same-sex couples
are substantially worse off", would it change your opinion? Would you read it
and think "Well, alright, I guess maybe same-sex couples shouldn't get
married"?

> EXACTLY. I don;t see how pointing the that one study is worse than just
> stating the fact/opinion...

Because you're selectively using sources to deceive people, if it's
intentional. It's a really powerful lie of omission.

> incontrovertible truth

What's an incontrovertible truth? Careful we don't side track into an argument
about incompleteness.

> the writer either needs to make a little effort to not be misunderstood or
> accept that some will completely misjudge where they are coming from (and of
> those two options I generally choose the first, you presumably prefer the
> latter approach).

My point being that people can always misjudge where you're coming from, no
matter what you say. In academic discussions and in didactic discourse, it's
important to make sure your audience understands you. HN posts are
overwhelmingly persuasive arguments (we're having one now, btw), and you're
diluting your message by sounding unsure of yourself.

------
comex
See also: "Is there a secure cryptosystem that can be performed mentally?"
[http://crypto.stackexchange.com/questions/844/is-there-a-
sec...](http://crypto.stackexchange.com/questions/844/is-there-a-secure-
cryptosystem-that-can-be-performed-mentally)

~~~
mistercow
That makes me wonder if any gangs have used Solitaire. Weaknesses aside, it
seems extremely plausible that you could actually share the keys in prison and
execute it. And a 225 bit key is nothing to sneeze at.

~~~
telephonetemp
On the other hand a substitution cipher is more resistant to user error when
encrypting or decrypting since such an error only affects a single character.
In secret prison communication you might not have the time to double-check
your encryption.

I wonder if imprisoned gang members have access to cell phones, though. They
probably do. You could run actual strong crypto even on a J2ME device (or a
gaming console, or a programmable calculator, or an MP3 player etc.) and I'm
sure there's plenty of people you could hire to write a custom-designed, one-
of-a-kind bespoke cryptographic app for a gang.

~~~
mistercow
I was under the impression that in prison, time is the one thing you have
plenty of.

~~~
telephonetemp
Time when you can fiddle with cards and write down cryptic series of numbers
without attracting undue attention is probably scarce.

~~~
mistercow
The cards just look like you're playing some form of single player game (hence
the name). If you had a journal to write in, then with some practice, you
could pass it off as idly playing the game while thinking of what to write.

~~~
DanBC
> write.

How many prisoners have free access to pens or pencils?

(Not snarky, I really don't know)

~~~
evacuationdrill
In a recent thread on reddit, a former inmate listed what was issued in
county/state/federal, and paper with a pencil or a pen with a rubber body was
in all of them.

~~~
telephonetemp
Can you give us a link?

~~~
evacuationdrill
I wish I could, but I can't remember what the thread was about originally. I
tried searching, but I can't find it.

------
colanderman
_One of the codes I worked with had multiple symbols for each letter. We have
26 letters in the English alphabet. But this code system had 40 symbols. The
letter “E” had three different ones. The letter T had two and so on. That’s a
very complex code._

Interesting; they're trying to flatten out the code distribution…

------
harywilke
Reminds me of The Wire episode "The Pager" (Season 1, Episode 5) where the
dealers were using a code to send numbers to pagers.
[http://www.youtube.com/watch?v=DQBlq45c1T4](http://www.youtube.com/watch?v=DQBlq45c1T4)
(clip shows the reveal of how the code works)

~~~
clebio
Had the same thought reading the article. Thanks!

~~~
clebio
In particular, the part about older members training the newer members on how
to use it. Oral history.

------
josephcooney
This seems like "cryptanalysis, circa 1600".

~~~
bediger4000
Indeed. Caesar Ciphers seem to be the hardest it gets. Did you notice that
this gang cryptanalyst actually described the famed "ROT-13" as a method the
gang members used?

~~~
16s
Triple rot13 (like Triple DES) is government approved.

    
    
        echo -n word | \
        > wm --rot13 --words stdin | \
        > wm --rot13 --words stdin | \
        > wm --rot13 --words stdin    
    
        result: jbeq
    

However, the result is the same as a single round.

    
    
        echo -n word | wm --rot13 --words stdin
    
        result: jbeq

------
strictfp
So, a simple substitution cipher? Should be trivial to crack.

~~~
smcl
For this guy yes, but for not necessarily everyone. The messages don't seem to
be particularly long so it's unlikely a frequency based attack could work.
Also if it is then these guys will not exactly be using the Queen's English so
they'll likely have a different letter frequencies for their dialect.

This lad in the article has a real knack for it though, I guess he knows the
subject matter pretty well (i.e. knowing the kind of things people will be
saying in certain scenarios, the word choice, how they address each other, how
the gang hierarchies work etc) and has a good mind for the kind of on-the-fly
ciphers that these gangs employ.

~~~
maxerickson
Frequency analysis works against a few dozen characters.

~~~
tripzilch
yeah. gp (and I recommend everybody :) ) should probably try cracking a few
substitution ciphers by hand just to see incredibly well frequency analysis
really works.

like you say, a few dozen characters of ciphertext. and you don't even need
the full frequency chart, either. just the top few is sufficient (there's a
lot of noise as you go down anyway because of Zipf's law). add knowledge of
the top-3 bigrams and trigrams, and you're all set.

it's all due to the fact that Shannon discovered, that there's only roughly
1.5 bit of entropy per character in English text. and English is in fact one
of the more efficient languages when it comes to this, Dutch or German have
even less entropy per character :) I don't know how it compares to Spanish,
however. gendered words are basically a type of redundancy checks, so they
waste bits in that sense.

~~~
smcl
I have, but I fail to see how frequency analysis can work on "Everything is
fine. Everything is cool here, uh, 15 22 27 31"

------
mistercow
Why do they have a human doing this? We have computers now, and solving this
kind of cipher is a Solved Problem. What this guy spends days on, a computer
could do in milliseconds.

~~~
phaer
I guess the problem is domain specific knowledge, user smcl did write
something about that below.

------
b0b0b0b
Reminds me of [http://math.uchicago.edu/~shmuel/Network-course-
readings/MCM...](http://math.uchicago.edu/~shmuel/Network-course-
readings/MCMCRev.pdf) using MCMC to break a prisoner substitution cipher.

------
Fundlab
Interesting

