[33c3 prelude music]

Okay, then let's continue with the next talk.

It's from vimja. He is from Bern.

He studies computer science
and deals with Bitcoin and Ethereum.

He wrote his bachelor thesis

on Bitcoin. So he will present us

an introduction to Blockchain.

A big applause for vimja!

[applause]
The stage is yours!

[applause]

vimja: Gret, that just 
broke down.

[laughter]

Now that's better.

[applause]
Thank you!

Okay, of course that
doesn't work, too.

Then I'll do it by hand.

It's probably because 
you consume all the wi-fi.

So the herald told you
everything already.

While studying blockchain,

I could learn many interesting things,

and I want to share a 
part of this knowledge

with you this evening.

This is of course a very
complex topic.

So let's start with somethig
easy, something we all know.

To be specific: conventional
systems of ownership.

They express who owns something.

These systems of ownership 
can be displayed as systems of transitions.

That's true for financial
systems

and for real estate
systems

expressing ownership of land.

The mapping consists of the 
collection of owners and their possesions.

And every shift of ownership

is a transition, that leads to a 
new steady state.

Concerning the financial system,
the state is

the collection of all the bank accounts.

And the transitions are 
between accounts,

for example transfering money.

That leads to a new state.
We see this here

with real estate as an example.
This state contains the information

of ownership for every piece of land.

Then Bob sells Alice piece of land Nr. 42,
that leads to a new state.

I marked the difference to make it clear.

It is important in all these systems
that all participants

agree on who owns what.

Because, if they can't, there could be 
attacks at the system.