My name is Konstantin and we're talking something about coupling Krakow with Ethereum

framework, Ethereum blockchain. I'm very sorry but my Linux on my

laptop cannot see the external display and I would present it under the markers and

there is no docker, there is no any practice. I would try to show you

how to practical work with blockchains, how to practical works with Ethereum,

but it will be just presentation and I would like to explain everything

better but with no practice. Sorry, that's my... Okay, let's start. A few words about

Ethereum. What is it and some terms, some concepts. First of all Ethereum is a

distributed network and like every network it has a nodes. What is a

node? Node on Ethereum or node on any blockchain. It's a, for example, server or

maybe it's a laptop and the software that's driven the node. We say that

software on a node it's a client. In Ethereum there are a few clients. For

example, it's official client. The client name has a name get. There are

official client by Ethereum foundation and there is some opposite clients

opposite not they have war with official client. Opposite like another

community, another community, another developers or something other. I use

the parity client. Parity is an organization that's just developing some

opposite clients for Ethereum. Also client is a software that encapsulates

virtual machine itself. What it mean? When you working with blockchain,

when you have deal with blockchain, you have a deal with a binary ledger on a

lower level and to communicate with this ledger you should have a virtual machine

that fetching binary data or pushing binary data to ledger. So every node in

a summary, every node running client software and this software

incorporates virtual machine itself to deal with blockchain. Okay some slides.

Oh it's slides shows us the terms of that I was talking about. Okay it's

something from a node. Client, yes I say it all. Client, node with a client and

parity is a client with a simple settings. About the virtual machine of

course. Oh another thing. It's what's about the consensus on a blockchain

network. When we say, when we're talking about blockchain, we are thinking

that there is a network and the nodes is a network storing data that's on trust.

What it mean? Every node could emit data and every node could emit transactions.

And all nodes should have an algorithm, should have a consensus to store data or

not to store data. There are different algorithms, but in the

stock, in a private network that I'll talking about, we use a proof of

authority algorithm. What it means? It means in your network you should say

this node or this node is authority and only this and only authority nodes could

sign transaction and could say okay your transaction is okay and your

transaction would be declined. Okay that's enough about algorithms.

Okay and what's about RACO? No problem we have a unit, we have a specific unit, the

package I mean that calling that has name netetherium. This unit I contribute

this unit it was ported from Perl5. Perl5 ecosystem has the same unit.

The author of the Perl5 unit also from Russia but the Perl5 unit netetherium

Perl5 package netetherium does not maintain anymore but in

opposite in RACO we I'm still working with working on this and maybe have some

fixes maybe some maybe it has some bugs but I think it would be fixed in the

future. This unit has a functionality to acquiring node acquiring client

on your node where RPC. It's very simple JSON data for requests, JSON data for

responses just parse it and do with it something you need. Communicate. Okay the special

thing is about it okay okay about the term special thing I would like to speak

about the smart contracts it's very it's very important because blockchain