
What Satoshi Did - mr_golyadkin
http://www.coinscrum.com/2015/10/29/what-satoshi-did/
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liamzebedee
One minor error, but the implementation of difficulty in proof-of-work is not
based on the number of leading zeroes, rather whether an integer is below or
above a target.

~~~
lisper
Those are the same thing when the target is a power of 2.

~~~
vog
Sure, but the PoW mechanism is more fine grained, and I think it is important
to point that out. Otherwise, people might indeed think that the difficulty
will always be a power of 2, which would mean that adjusting it would have
been harder (and more inaccurate) than it really is.

~~~
lisper
I dunno, that seems like a pretty small nit to me. But I suppose reasonable
people could disagree.

~~~
arcatek
I've worked on a coin, and this kind of inexactitude are what make it really
hard to understand how the implementation works (that, and the fact that the
code was hell at the beginning). If the code uses a "less-than" operator, just
tell it. It makes no sense to use a different terminology (in this particular
case, the "number of leading zero" concept was probably used to make it easier
to understand for business guys - it doesn't work quite well).

~~~
vog
Moreover, I believe that talking about plain numbers and "less-than" actually
makes explaination easier, compared to talking about strings and leading
zeros.

Using plain numbers, I would explain it to a layperson like this:

 _The hash is number from 1 to 1,000,000 (actually, it 's a lot larger and we
are counting from zero, but you get the idea). You can't control how large or
small the value is. If some people generate a hash of 10,000 or below, this
means they had to try roughly 100 times, computing 100 hashes, until they
found that one by chance. This is a "Proof of work". If you reduce the
threshold from 10,000 to 5,000, people will have to compute on average 200
instead of 100 hashes. So the smaller the threshold, the more difficult the
challenge is to solve._

On top of its simplicity, this explaination has the advantage that the
statistics are pretty obvious and don't even contain exponentials or
logarithms, which you would have to use when talking about strings and leading
zeros.

~~~
xxs
_You can 't control how large or small the value is. If some people generate a
hash of 10,000 or below, this means they had to try roughly 100 times,
computing 100 hashes, until they found that one by chance._

Not to be blunt, yet after 100 attempts w/ 1% positive outcome, there is
roughly 63.3% odds to actually succeed.

~~~
tromp
The expected number of trials, each with 1% of success, is 100 though.

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grabcocque
One of things I find fascinating is exactly why Satoshin has proven so hard to
identify.

In truth there's probably only about twenty people on Earth who have the
requisite skills, knowledge and obsessive personality to pull off what they
did, and you'd think somebody like that would be well known in the security
community. It should be EASY. But the mystery endures.

~~~
badloginagain
I speculate that it isn't, and/or has never been a single person. It's likely
that its a group of people who use Satoshi as obfuscation and branding. People
want to believe that an ubermensch cryptographic Einstein is among us, single-
handedly dragging us into the future. It's high drama for a fairly dry
industry.

It's stands to reason that the more boring answer is correct- that Satoshi is
a group of people from the beginning working on the blockchain and the
ideology behind it. This allows the Satoshi Group to engage in public
discussion about the 'chain without the starry-eyed bullshit of celebrity
appeasement.

~~~
greggarious
Comedy option (not seriously proposing this): Some gov't agency or group of
non state actors looking to have an untracable source of income invents the
bitcoin. This is why Satoshi never cashed in their coins - the idea was you
invent the protocol, then make your money by being one of the early miners.

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HappyTypist
For the record, this is quite a simplified overview of proof-of-work. It
ignores the complexities of network propagation speeds and orphaning, which
can result in withholding attacks being more effective. Proof of work is not a
magical bullet -- although, arguably it is the best one we know of so far.

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garrettr_
> By ensuring that no person could obtain an advantage over others, and by
> ensuring that anyone could join without exclusion, Satoshi created the Nash
> equilibrium to permit normally byzantine parties to enter and share safely
> in the definition of a shared network of contested assets.

This is roughly true, although Nakamoto's original paper only proves this for
the case where no single entity controls > 50% of the mining power in the
network (weak incentive compatibility). Nakamoto argued it was also true for
the case where a single entity controls > 50% of the mining power (strong
incentive compatibility) but failed to prove this, instead providing a vague
argument based on some difficult-to-prove assumptions.

For more information, including an interesting theoretical attack based on
this idea, see
[http://www.jbonneau.com/doc/BFGKN14-bitcoin_bribery.pdf](http://www.jbonneau.com/doc/BFGKN14-bitcoin_bribery.pdf).

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jgalt212
What's the economic incentive for the ledger keepers and verifiers once all
21MM bitcoins have been mined?

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mgalka
Considering they just arrested someone rumored to be Satoshi, I thought this
was going to be about why he was arrested.

Good post though, well explained.

~~~
EGreg
[http://badsatiretoday.com/satoshi-nakamoto-founder-
bitcoin-a...](http://badsatiretoday.com/satoshi-nakamoto-founder-bitcoin-
arrested-identity/)

~~~
tedks
That's from a year ago. An Australian rumored to be Satoshi was raided
recently.

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speaker5
Is there a link to something about this?

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ddeck
I would suggest googling the three words "bitcoin Australian raided"

Every result on the first two pages points to this.

