Building on a blockchain – EDU 03 2018

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6 June 2018 | 11:00-12:30 | EVENT ROOM | YouTube video
Consolidated programme 2018

Session teaser

Join us for discussion on the most talked-about issue on the Internet. We will try to explain how Blockchain works, what the main characteristics of cryptocurrency mining are, and how smart our future contracts can be. Knowing the basic framework will help you understand the potentials of this novel technology.


Blockchain, cryptocurrencies mining, cryptocurrencies, smart contracts

Session description

Link between blockchain powered solutions and the future privacy and safety paradigm change, is becoming stronger and clearer. Not only in data governance, but also in wider governance issues, blockchain can help in control of personal information and other valuable information on the network. Session will start with the main explanation of the blockchain technology, and we will continue with the interactive game of creating one analog blockchain. Game will involve the audience. After this, we will try to bring you a closer look at the idea behind the blockchain powered ‘smart contracts’


Panel, interactive game with audience.

Further reading


Focal Point

  • Arvin Kamberi, DiploFoundation

Organising Team (Org Team)

  • Enzo Puliatti
  • Katie Kochladze
  • Jörn Erbguth
  • Debora Cerro Fernandez
  • Walid AL-SAQAF
  • Michael J. Oghia

Key Participants

  • Enzo Puliatti
  • Walid AL-SAQAF
  • TBC


  • Arvin Kamberi

Remote Moderator

The Remote Moderator is in charge of facilitating participation via digital channels such as WebEx and social medial (Twitter, facebook). Remote Moderators monitor and moderate the social media channels and the participants via WebEX and forward questions to the session moderator. Please contact the EuroDIG secretariat if you need help to find a Remote Moderator.


Reporters will be assigned by the EuroDIG secretariat in cooperation with the Geneva Internet Platform. The Reporter takes notes during the session and formulates 3 (max. 5) bullet points at the end of each session that:

  • are summarised on a slide and presented to the audience at the end of each session
  • relate to the particular session and to European Internet governance policy
  • are forward looking and propose goals and activities that can be initiated after EuroDIG (recommendations)
  • are in (rough) consensus with the audience

Current discussion, conference calls, schedules and minutes

See the discussion tab on the upper left side of this page. Please use this page to publish:

  • dates for virtual meetings or coordination calls
  • short summary of calls or email exchange

Please be as open and transparent as possible in order to allow others to get involved and contact you. Use the wiki not only as the place to publish results but also to summarize the discussion process.

Get involved!

You are invited to become a member of the session Org Team by subscribing to the mailing list. If you would just like to leave a comment feel free to use the discussion-page here at the wiki. Please contact to get access to the wiki.


Find an independent report of the session from the Geneva Internet Platform Digital Watch Observatory at

Video record


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This text is based on live transcription. Communication Access Realtime Translation (CART), captioning, and/or live transcription are provided in order to facilitate communication accessibility and may not be a totally verbatim record of the proceedings. This text is not to be distributed or used in any way that may violate copyright law.

>> Just wait a few more minutes and we'll start. Thank you.

>> ARVIN KAMBERI: Okay. I think we can start now. Hi, all, and welcome to the session, which is "Building On Blockchain," Arvin Kamberi from DiploFoundation and I will be moderator of this session. I would like to point out that this is a session for the newcomers. This is the basics about blockchain and why we are doing this again, as a -- for the newcomers session is because a lot of people are coming to EuroDIG are first comers. A lot of them are just to be introduced to many technologies we discuss or many issues around technologies we discuss.

And to be honest, after 15 years of Internet governance we have sessions how do the internet works and this is explaining basics of things that can be built on a blockchain.

For everyone who would like to discuss -- how can I say -- more complex issues on blockchain, related to governance, et cetera, I will invite you to join the session after the lunch, in which we will discuss a bit more on other issues from blockchain. That session will be led by Jörn here. If you are more aware of blockchain, this may be a bit boring for you. So let's see.

Since the same of this session is "Building On Blockchain," I will actually like to focus here on two things that are actually working on blockchain right now, and so far to be honest.

One of them is network of transactions, and the second one is smart contracts. So having that in mind, I would like to introduce my colleague panelists here today, to my left is Walid Al-Saqaf from ISOC. And he will give us a short introduction afterwards. Next to me on my right is Jörn Erbguth, a blockchain consultant, working also as a professor.

>> JÖRN ERBGUTH: Lecturer.

>> ARVIN KAMBERI: So let me explain how the session will go. We will have Walid explaining the main features of blockchain. You have probably heard it so far, the transparency et cetera, but we will allow Walid to give us an introduction on that. After that, we will showcase how network intersections work. And, of course, this will be done with your involvement. You will be involved in this as an audience.

We will try to send some of the currency between you guys here in the room, and in this case, in our case, the currency will be the chocolates. So we will prepare here chocolates so you guys send chocolates to each other, just through our analog representation of blockchain. So that's how we are going to do that.

After that, we will have a presentation from you on smart contracts. This is another thing which is actually quite vivid in blockchain, working fine on there. Smart contracts would be interesting for both -- particularly interesting for people with both technical and legal background, I guess some of you had that also.

Following that, we will have a round of Q&A because this is an educational session, we will try to put the Q&A as much as possible so you guys can ask whatever.

Without further ado, I would like to start with this session, because I think we might fit everything in 80 minutes we have. So let's start.

Walid, please, go ahead.

>> WALID AL-SAQAF: Okay. Thank you, Arvin. First of all, let me say that I hoped to -- the idea of looking into blockchain and particularly at the very outset bitcoin, because it resembles some of the main characters of how the Internet evolved.

I come from a computer engineering background, academically speaking and so I witnessed the evolution of the Internet from the very beginning, and so I felt like nostalgic to the early days when the Internet first emerged. So it made me wonder whether the same direction will be taken in the case of blockchain. To some degree, I see very similar -- many similarities.

But let me start with some very broad notions. The internet, we are at an Internet event today. So the Internet's main characteristics are very clear to money, which is decentralization. So there's no central authority in control. No one can say, okay, I will shut down the Internet today or looks into all the traffic going on through the Internet. That's one thing.

Another thing that it's transparent in the way that the routing mechanism, the TCP/IP protocol, everything is open source. So you can actually understand how it works seamlessly across borders and throughout many different channels. And thirdly, it is secure. Secure in the sense that you expect the packets will be delivered. You know that if you send an email, and everything goes right, then the email would arrive.

There are other things like malware, et cetera, they are not part of the framework of how the Internet works, but the way it functions makes it, let's say, immune from, let's say, being error -- it has a way for checking errors, for example, and all sorts of things that make it rather reliable.

And so the only issue with the Internet is that it allowed us to communicate. So it allowed me to send anyone an email across the world or any form of message across the world, but the problem with that is that if you send multiple emails or multiple communications, then you are duplicating the same content. So it allows you to copy, copy and paste, and replicate, et cetera. It's one way of communicating. It works good, but it's not possible to use the Internet to send value. So it took a long way until 2009, when a guy or a group called Satoshi Nakamoto who said we should use the Internet not only to communicate but to exchange value, in the sense that you can now -- if you have a particular thing of value, like in this case bitcoins, you can use the Internet to move bitcoins from one position to the other.

In this case, unlike the way in which you communicate and send data, you actually remove the data from your side, and it suddenly appears at the end, meaning that ownership of the data changes. And so this is revolutionary. You no longer need banks or central authorities, but the way you think of it is that the main idea between blockchain and bitcoin is they wanted to eliminate the need for a third party. It was a peer-to-peer system. You need to be decentralized. You need to be, of course, secure, and you need to ensure that there is no way for manipulating or going -- trying to change the data.

And so what happens, instead of having the ledger which is often used as the form of explaining what blockchain is, a ledger of accounts, this ledger will be distributed and available across the world throughout all the nodes that are connected to the system.

So it means that if someone tries to manipulate the ledger, that would be caught easily, because the copy of the ledger, that is securely kept in every single computer will be the same and so there will be a problem because one of them had been illegally violated the rules and tried to breach the consensus within this group. So that meant that it had to be a strong way of having consensus. You had to be decentralized. You had to be what we call immutable, meaning no one can change the record without consensus.

So these are what made bitcoin rather the disruptive technology that we know of today, and basically blockchain as an idea emerged from the operation of how bitcoins operated. You need to give credit where credit is due, and explain that blockchain became the notion, the buzz word to describe how bitcoin and have consensus.

I know we have limited time to discuss, but one of the main form of peer-to-peer networking or payment system is to arrive to consensus without a third party and that's one of the objectives of the training exercise.

How on earth can you arrive to consensus if you all have the same authority? And so the game that we will demonstrate today will help you understand how it is possible to do that and why this new idea is revolutionary in many ways and we will have a Q&A part to discuss more.

Thank you.

>> ARVIN KAMBERI: So thank you, Walid. And let's start with this -- we'll start with this game.

First, what we showcase is the network of transactions. So I will -- actually, let me just stand up, go there and I will ask for eight of you guys who would like to volunteer to be a part of our network. Can I see hands?


>> WALID AL-SAQAF: Come on, don't be shy.

>> PARTICIPANT: There are chocolates, right?


Here you go.

(No audio)

Thanks. So I bet you all heard -- this is for remote participants to repeat.

You heard about hashing and hashing is really something which is related to the blockchains after all.

So basically, this is -- this is the main feature of hashing is to have a number to combine a large -- a large data into a smaller number. But even if something even slightly changed in this data this number would be in the end completely different.

For example, you see this slide. The text is -- the only difference is this G, and you can see. Here is a small case, here is an upper case G, producing a totally different hash. So that's the main purpose of hashing. Hashes are used heavily in the blockchain interval and mimic a bit simpler hashing today.

Can I have a second slide, please, the next one? No, no, no the previous one.

Okay. So this is a transactions and this is how we are going to start doing actual -- actual network transactions right now. So we will -- we will keep the genesis blocking, which all of you guys actually have the chocolates and I will just deliver it to you.

So let me see who was that -- who was the minus? That's you. Don't eat a chocolate still. You need to send it to someone. It's six, eight, ten for you.

Okay. Let's distribute this around. And it's 20, ten for you, ten for you, is it? Three, five, and five. Oh.

Ten for you. Yes, distribution is hard.

Was there anything -- oh, here we go. Three, six, nine, ten. This is your initial loot, yeah? Three, six, nine, ten. Of course, you can spend your currency. He can eat it.


We will not have anything to transact with, you know?

Five, ten. Yes. Anyone else? Did I miss one? Oh, sorry. Three, six, nine, ten. And the number four, yeah? You are the number four?

Three, six, nine, ten.

Anyone else? No. That's it.

>> PARTICIPANT: Thank you!

>> PARTICIPANT: What is the status of that?

>> ARVIN KAMBERI: Just a friend.

(Off microphone comment)


>> PARTICIPANT: I really think you did not do justice. It was your friend. I would like the idea of --

>> ARVIN KAMBERI: He's not going to be in the game. He just wanted to eat it because he's low on sugar now. He's not in a game. He's just like had a droppage of sugar in blood. So he needed chocolate. That's it. So he's out of the game. He doesn't have a number.


First of all, why you guys get a number? This is a representation of wallets. You heard about that. This is your personal number in which you can receive and send any kind of currency or any kind of, in this case -- in this case chocolate, but this is your personal identifier in this network. So all of you guys have a personal number.

So let's see how the actual transaction works. First of all, transaction needs to have a time stamp. It needs to have a number center, an identifier of a center, the amount of units sent, the identifier of a receiver and at the end, there is a fee. All networks actually works with the fees, all transactions works with the fees.

We heard there is no intermediary to pick up the fees in it, but there are miners or people who actually work the intersection, validate them and as a reward, they get the fees from the transaction. And, of course, as an additional reward, they gain a newly minted or newly created currency or amounts -- amount of units.

So for this game, as you heard, Walid at the beginning, the most important feature of blockchain is actual transparency. So we will actually call out our miners to try to help us.

Laura, can you be one miner? Janna? Okay. Michael.

Well, Michael, we will need a little bit later. Let's have two miners first. Guys are going to be miners and actually --

(Off microphone comments)

>> ARVIN KAMBERI: Yes, that's real important.

And now, let's make transactions. Who will send -- let's take three transactions from you guys with chocolates and sending somewhere else. Let's do it. Come on.

Can you announce your transactions? Anyone? Okay. Go ahead.

(Off microphone comment)

>> ARVIN KAMBERI: You see? And what is that fee? What is the fee? You will need to have some kind of fee that your transaction is going at. One chocolate. Okay.

So let's write that down. Your number -- let's have this format, write it down. First of all, we need a time stamp. So we will look at the watch and it says 11:20 so let's use just minutes. Let's say 20, 2-0.

Center, your number is -- your identifier number is 6. Sending five chocolates you said?


>> ARVIN KAMBERI: Five to number three, yeah? Is that right? Be the fee of one chocolate. Okay.

So this is one transaction. Let's have another one. Let's three transaction. Go ahead, please.

>> PARTICIPANT: Okay, I will send three chocolates to number four.

>> ARVIN KAMBERI: Three chocolates for number four. And what fee?

>> PARTICIPANT: I don't understand the idea of this fee. Can you explain it again?

>> ARVIN KAMBERI: The fee?


>> ARVIN KAMBERI: The fee.

>> PARTICIPANT: Why do I decide about it? Do I decide about it?

>> ARVIN KAMBERI: Yes, we will show a bit later, why it is important.

>> PARTICIPANT: Okay. Two.

>> ARVIN KAMBERI: Two is the amount you need to go. You are writing it down. Now it's 21. 21 minutes. Your identifier number is number 4. 4. With a fee of two.

Go ahead, please. (Off microphone comment).

>> ARVIN KAMBERI: Sorry, I couldn't hear you. Sorry.

>> PARTICIPANT: I will send three chocolates to number 3, with a fee of one chocolate.

>> ARVIN KAMBERI: Please, your --

>> PARTICIPANT: My number is 8.

>> ARVIN KAMBERI: It's 22 now time stamp. Your number is 8.

>> PARTICIPANT: With a fee of one.

>> ARVIN KAMBERI: Okay. Those are three transactions right now, and let's drive our miners to work on it. How are they going to work on it and what's important?

Well, from this number -- let's first answer your question, why we had the fees and what's -- how -- why is this important?

I will now, for example -- fees actually works as an incentive to the network, to the minus. Because there is no central institution to take the part of the intersection, minus took the part of the intersection, and the fee actually incentivized them to be a minus.

Once they create a block, they will also get a newly created chocolates, but you will also get your fees or fees from the transactions. So that's an incentive for them to actually be and verify this network, and to work on it, to work on your transaction going through.

So if we now ask minus, what will be the first transaction you will work? What is the first transaction you will work?

>> PARTICIPANT: With the biggest fee, of course.

>> ARVIN KAMBERI: So they will first work on this transaction. That's the basic incentive around the network. And it actually explains how the network will work after everything is mined. You heard about miners and mining new currencies, but at the end, the currencies might stop. Like bitcoin has 21 million bitcoins and when all are mined, what is in.? What is the incentive for them to work on it? So the incentives under fees. So this is the basics.

Unfortunately, I think that -- number one, yeah, number one we will get first.

>> WALID AL-SAQAF: You recall in the peak of 2017, there was a huge scalability problem in bitcoin, it took many, many hours to get through the transaction.

The reason is that people had to increase their fees and came up to $22 per transaction and it was quite heavy.

That is a reason that fees may a role to get transactions faster. Are.

>> ARVIN KAMBERI: Yes, thanks, Walid.

I didn't know you were going to be so short.

So now we go to the hashing, the previous one we saw. Where do we use now a representation of whether hash really is and we will try it with adding hash and what that basically means. We will add plus here and summarize it to be one number.

According to that number, we will choose the question or how can I say -- do you have pens?


>> ARVIN KAMBERI: Please sum it up and make the hash out of it. You just like plus here also. So just came up with that number.

What is it? No, two plus one, plus -- so it's what? 14? And reduce the one number, to single digit number, it's five.

Okay. So previous slide, can you? Can you do the previous slide? Is it? Maybe she's not so good at math. Let's see. Two plus one is three, four, seven, 11, 13, yes.

This is not done by people, but actually graphic arts, which are way better in math.

>> PARTICIPANT: That's why I needed a chocolate before.


>> ARVIN KAMBERI: Okay. So you guys are going to do a second transaction. And why we needed a hash? Hash will actually, as you see -- so we know that this comes up to four. But when you see number four, we don't know what was the inputs. So basically, that's the representation.

Go ahead, go ahead, go ahead. Please.

>> PARTICIPANT: Sorry. We came out at 13. What is the four for?

>> ARVIN KAMBERI: We wanted to have a hash, a single number. So one plus three is also four.


>> ARVIN KAMBERI: Just hashing until we get the simplest number. Why we need that number is to actually have a question. You heard about that miners are working on a hard mathematical problem, you know, you know when they sold it, they are rewarded and the block is created. But what is this hard mathematical problem? It's actually about guessing. It's a sheer number of guessing the answer. This is not a quiet -- there is no other way to calculate except guessing it.

So in order to have a most proper guess for you guys, we will have hash number four questions and you will do a maze. Why a maze? Let me explain this.

It's most -- it has to be done by tries and errors. So this is the closest representation of what a hash actually are -- how you solve the block of a -- do a block.

So guys, I made for you. And same for you.

Before you start, let me just explain. The first one who actually did it, will announce it, and another miner will actually check if that's all right. If it's okay, that it's propagated through the network and that's the solution for this block.

So let's start now.

>> PARTICIPANT: Yeah. And I have here some music to play.

>> ARVIN KAMBERI: Well, getting chocolates is not easy. Working is actually -- go ahead.


>> ARVIN KAMBERI: Got it? You have to check it if it's true.

>> PARTICIPANT: I understand this is the combinations of numbers come to the number four.

>> ARVIN KAMBERI: Just a second. Just a second.

>> PARTICIPANT: No, just to understand it, in practice, does this mean this -- the thing that they are doing now is they are trying different combinations --

>> ARVIN KAMBERI: Exactly.

>> ARVIN KAMBERI: So combinations -- (Overlapping speakers).

>> ARVIN KAMBERI: Yes, until you find a solution.

Go ahead, please.

(Off microphone comments)

>> ARVIN KAMBERI: Sorry, go ahead. Please use the microphone, if you can.

>> PARTICIPANT: You put the time clocking, no? So they have to be also and see who is the different path or who is the fastest one?

>> ARVIN KAMBERI: Who is the fastest one? Yes.

>> PARTICIPANT: So that is what that thing is for, no? Because there are different mines working at the same time for same thing?

>> ARVIN KAMBERI: Yes. All miners are working on the same block. Join us here.

>> WALID AL-SAQAF: The miners decide on what block to form, based on the transaction. So they decide on the second transaction, they decide that might well be the different transaction. It doesn't matter much. The moment that they announce that they have a block ready, based on the transactions available, that is when the -- the -- their block is checked to verify that they got the right answer, based on the transaction.

So the solution of the maze now will have to be checked by the miners, as well as the regular nodes if they are interested to verify that and from that point onward, the whole -- the transaction that the other miner has been working on has been taken. It's no longer there. So they have to start all over again with a new transaction.

So that's how the process goes.

>> ARVIN KAMBERI: Thanks, Walid. You had a question?


>> ARVIN KAMBERI: Prior to you getting your chocolates because you are the receiver of this.

>> PARTICIPANT: Yes, but I still don't quite understand who in the first place generates these hashes, that then they have to, like --

>> ARVIN KAMBERI: The transactions. Let's have another -- the second slide, please.

You remember this was a transaction. So from this transaction, hash is created from this transaction. It has unique time stamp, et cetera. And so it's from transaction. We write it down in this form.

>> PARTICIPANT: What agent or whatever creates this hash?

>> WALID AL-SAQAF: Basically the whole rules applies that every miner has created in such a way. It's like the github files on bitcoin, the bitcoin structure is how this standard format needs to be done. Every miner needs to apply the exact same rules.

>> PARTICIPANT: Before we start the maze, we do the hash. It's the miner who does it, right?

>> ARVIN KAMBERI: Exactly, it's always the miner.

>> WALID AL-SAQAF: The miner creates the hash but then needs to solve it back to its original?

>> PARTICIPANT: No, no, it's different.

>> PARTICIPANT: So it's one miner who does the hashing and there's another one who solves it?

>> ARVIN KAMBERI: No, no, no.

>> PARTICIPANT: I have the same path as he does, but I have left and the mode said I'm done. I was like, oh, done. But we are doing the same thing -- we receive the same transaction.

>> ARVIN KAMBERI: Just one by one, please.

>> PARTICIPANT: We saw the transactions. I'm writing everything down too, but we just detached two things. Three transactions, plus solving the puzzle. You connect them together. These two are detached. Three transactions. They are kind of hashing and respective rewards per transaction, plus solving the puzzles. These two are detached right now.

Now you connect them. How these two are connected, I'm asking?

>> ARVIN KAMBERI: Go ahead.

>> PARTICIPANT: So I'm trying to see the view of a miner, trying to earn money. I'm looking at the fees and I say I like this fee. I start with this one first. I do the hash because we need to do the hash, because what they are going to further explain. To be the one to verify the transaction, I need to solve the puzzle and so does she and many others who say I want to do this one. So we all do the hash and then we compete to who will be the first transaction.

This time, I want and she gives up and turns to another transaction, and we start again.

>> PARTICIPANT: So you get all the fees for all the transactions?

>> PARTICIPANT: For this up with. For one I solved.

So now we are moving to the next transaction.

>> PARTICIPANT: I thought this puzzle was just for all of them.

>> ARVIN KAMBERI: No, it's just for one. Let's dot transaction, actually, what was that? They need to be detached from the chocolates. Three? It's for you, yeah? Oh, here you go. You now have a bigger load, this is a fee for the miner, the miner who actually solved the transaction and apart from this, here you go, Walid. The minus ones they have done with the block, they also get the newly created units.

Necessity solved the block. They get rewarded. From the initial number, is that okay?

>> PARTICIPANT: It's not clear.

>> ARVIN KAMBERI: Just a second. Just a second. Go ahead. Go ahead. Go ahead, please.

>> PARTICIPANT: Well, it appears that maybe in this simple simulation, if you solve a puzzle for each transaction, then you open a block, but actually, each block contains a lot of transactions.

>> ARVIN KAMBERI: Exactly. Okay. In this, we might have missed this they beginning. Our block has one transaction. It's a really small block. It's really one kilobyte block. It contains only one transaction. Only one.

>> WALID AL-SAQAF: And the one who minted the coins is not included because it will complicate things.

>> ARVIN KAMBERI: Walid, why don't you join us to show the --

(Off microphone comments).

>> WALID AL-SAQAF: Now you actually begin building the blockchain. Where is the pen?

So now you already started and have -- you had the earlier blockchain, the blocks which were the genesis, et cetera. But now the newly created block is the --

>> PARTICIPANT: (Off microphone comment).

>> WALID AL-SAQAF: So it's now won by a number -- the number of the block, the hash four.


>> WALID AL-SAQAF: And your number. So you can say this is the number of the -- I mean, for our demonstration purposes, we can say this is the block number that peace been won. And you can refer to now the winner and you know the -- the hash transaction.

So in this case, you now have the one block and this needs to be the same, not only here, for every single member of the network. They need to have this number in their blockchain. And so 42 is the number of the block and that's how you begin to block after block. So that's one way in which you can think of it.

>> ARVIN KAMBERI: Stay close. So now for the second transaction, we will include the number of miners. Michael, you volunteered. Please go ahead.

Yes, please go ahead.

Can you write down those blocks?

Okay. Please. Of the second one is -- so just to -- yes, this one is done.

>> PARTICIPANT: So start at 21?

>> ARVIN KAMBERI: I will do it for you. Thanks.

So let's just do the first one. It was 20, 6, 5, 3, 1. Here you go. And we will trust Laura would said that this transaction is eight. And we will do the second one, 22, 8, 3, 3, 1. And the hash with that is one.

Thanks so much. Here is your pen.

So what you guys are going to do, decide. Which one is it going to be? First one. With the number eight. Go ahead, please.

>> PARTICIPANT: We still don't understand why you gave him the additional ones from the back.

>> ARVIN KAMBERI: Okay. Let's say -- well, the network --

>> PARTICIPANT: They're friends.

>> ARVIN KAMBERI: No, no, no.

Well, you probably heard that cryptocurrencies are not already mined. This came in a case that they were not already mined. This is also incentive to miners to actually do their work. So when one block is created in our case 42. The newly created currency is issued.

For example, so far we have 17 million -- let's say bitcoins, we have 70 million bitcoins and how they are put in the system? They are put in the system -- whenever there's a new block, the new block release a new number of units into the system. This is a reward for a block find. This is a reward for miners for the block find.

So for example, in bitcoin now, there were 15 after of hashing. 12.5 bitcoins. So whenever somebody creates a new block, new 12.5 bitcoins are actually in the networks. They are created by myself. They created by the creation of this block. So this is an incentive. This is a first major incentive for the miners.

But then all cryptocurrency is mined it won't be newly created. So then miners only work for fees. So that's why it has only fee and new -- does it explain a bit?


It sounds like magic.

>> ARVIN KAMBERI: Yes, it's all mathematics. It's magic. It's happening.

>> MICHAEL OGHIA: It's not just incentivizing the miners so that they can make money. It's also a way to incentivize the cost of the electricity because it is a very energy intensive, you know, process, one of which if -- especially if miners are using -- are heavily invested in mining bitcoin, the cost can be in the thousands per month to the cost. Try to make that connection to a more tangible output as well.

>> PARTICIPANT: What comes to my mind as a miner? How does it come that there's new currencies actually? When I mine gold, actually, I dig the gold. Now, in this case, I would get both the gold and be paid. And we dig more gold and as we dig more gold, we get more gold and at some point there's more gold that we can dig. There's no more gold we can take and we just take the transactions.

But as long as there is more gold to mine, we get both the gold and the transaction. That's the system, but that's how it goes.

>> ARVIN KAMBERI: Yes, it is magic. Magical math. Go ahead, please.

>> PARTICIPANT: I have another question regarding to solving the maze. You said before, well, if you look at the numbers, there's more than one solution that fits this scheme that we have now.

Is it that if you solve them, there will be only one solution that fits like this particular format?

>> ARVIN KAMBERI: Yes, but let me --

>> PARTICIPANT: So how do you --

>> ARVIN KAMBERI: This is the simplified version. The previous slide, please, can you -- this is how the actual hash looks like. It's really hard to, you know -- it's almost impossible to kind of -- I understand that in this plain level, you know, you can have number one, maybe, two or three times but hash are quite complicated, actually. As you can see here, if you change anything, any information, even smallest information in transaction, then that hash will change.

Why is this important? Because this hash is implemented in the block. So if someone tries to change anything in transaction, the hash will change and it will not respond to the other blocks. Meaning it's incorrect. Meaning that someone has tampered with it.

Does that explain a bit?

>> PARTICIPANT: Yeah, but, like, the question is like if you are so -- if you need to solve it back in order to get the transaction right?

>> ARVIN KAMBERI: No. No. No. You can get information from hash back. You can't -- you can't -- you know that this is always this.

>> PARTICIPANT: It's a stamped significant.

>> ARVIN KAMBERI: But, please we have --

>> PARTICIPANT: You only have one signature. You don't need to return it back to the message. It certifies that that's the message that you sent.

>> ARVIN KAMBERI: But we are short on time, so let's try to continue and why we actually introduce Michael as the third miner to explain a bit.

So you guys are going to work on the first transaction, right?


>> PARTICIPANT: By the way, Michael, you may want to use another transaction.

>> ARVIN KAMBERI: Let's all do the same. Well, we increase the mining power, the difficulty of the maze or let's say a problem, which is solved is actually increased.

So they will now, because there's three of them, will have to do even complex, even more complex puzzle. So that -- go ahead, please.

(Off microphone comments)

>> ARVIN KAMBERI: Yes. Yes. Exactly. So we just try to simplify it here, bust that's exactly the case.

So that's why guys you have a bit harder puzzle this time. Because you had a competition and you need to work harder.

One for you. Let's have the same start. Are you all set?

Okay. Go.


Come on. It's not so hard, is it?

They go one way, and it's a dead end. This is how it's solved by trial and error. You know, you have a mathematical formula how to solve it.

You need to try it this way, this way, this way, until you find a solution. So it's -- this analogy, this maze is --


Oh, sorry. Yeah, you are right. I tried maybe just because we are short on time. That's scary music.

Anna is close. Yes, she is. Mm-hmm.

>> PARTICIPANT: It's copyrighted.

>> ARVIN KAMBERI: Is it a copyrighted, really?

Maybe this was too heavy for you guys. You need improvement in graphic arts. Go ahead.

>> PARTICIPANT: But this can happen with bitcoin. It could be that there's no bitcoin for a half hour or so because the miners are not finding a solution.

>> ARVIN KAMBERI: Exactly. In bitcoin blockchain, this will be created in ten minutes. Every ten minutes there will be a new block. So they had easier -- they had easier puzzle and they solve it in like five minutes.

And the next block, the -- as we saw the algorithm will increase the complexity.


>> PARTICIPANT: I got it!

>> ARVIN KAMBERI: You got it, but guys need to check, it actually. You need to check it. Is it true? Metrics needs to check if this solution is truthful.


Congratulations to Anna. Please check that that is the proper case. So this was the transaction. What was the transaction?

>> PARTICIPANT: Do we have a copy of the puzzles.

>> ARVIN KAMBERI: You can verify the other thing. Yeah. It's transparent. That's why we are doing it in front of everyone. What was the transaction? Number six.

Who is number six? Who? You? You send five chocolates to number three. Hmm, three, five, six. Okay.

Who is number three? Oh, that's for you. Okay.

That was pretty generous, five chocolates. And the reward for the miner. Miner, this is a fee. And this is a newly created units.


>> WALID AL-SAQAF: So the transaction code, what was it?


>> WALID AL-SAQAF: And so this is what they got. So the thing is that now the earlier one, we saw genesis. We thought it was 00. This is 42 and this is 81. So the new block will actually be what is called the Merkel three. And so it has to be a hash of 42.81 and that will be the one here. Maybe you can add them together, 9, 11 --

(Off microphone comments).

>> WALID AL-SAQAF: No, her -- she's the winner. So is it 60 or is it -- 15. 15, let's say, because multi-digits. So let's -- it's not a hash, it's just hash one time. So in this way, we can tell how these are interrelated. So if this was removed for some reason, this number will change. So this is like a continuous and the new one will be like that. So that new one will depend on the hash of the new one. They are all interconnected to each other. And that's how the new one is corrected. That's 15 and the same block number will be on every single node on the network. And so that's the new block has been mined.

Good. Shall we continue or is that --

>> ARVIN KAMBERI: We are running a bit out of time because, of course, we have another presentation.

So -- sorry. Yes, we will not do the third one because the time restrictions.

So while we will have another presentation now on smart contracts. Thank you, also. And of course, you can eat your chocolates and we will now have Jörn, with another really important feature of blockchain, which is smart contracts. Please listen to Jörn.

>> JÖRN ERBGUTH: Hello. So who has already heard about smart contracts?

Okay. Can you say what a smart contract is? Can you -- can you say what a smart contract is?

>> PARTICIPANT: Thank you. Hello, everyone.

Smart contract is an online transaction when you can just sign any document online and it's like blockchain works, it's hashed and kind of very secure and stuff like this. I have just general idea about smart contract, is it's affordable, easy and very secure. It's like based on the blockchain system and stuff like this.

Maybe I'm not -- but you are going to explain it.

>> JÖRN ERBGUTH: Okay. Thank you. Actually, what you can see is that smart contracts is something that is not really very sharply defined. Everybody understands something else from the term "smart contract."

It has something to do with contracts. It has something to do with online. It has something to do with secure. It has something to do with automated, but the definitions vary.

I want to bring down three concepts. One concept is that you do a contract not by legalese, but something by a contract, by a code and the second one is that something is executed automatically. So it's not a contract that people manually execute but that is executed by a computer.

And the third thing is that it's on a blockchain, which is the element of trust. So going to the first one, the question is, can actually a code be a contract. A legal contract? And was the question more general, can code be law?

And if we both want to do a contract and we both understand Esperanto. If we both understand solidity, the smart contract programming language, we can do it in solidity. No question about it.

So the legal system says, of course, you can use any language you want, but it has to be understood by the parties.

Then the question is: Is this our contract or what is the contract? The contract is abstract legal construct. This means that a contract is not the legalese, not the writing, the paper writing.

You can go to a bakery and buy some bread and you don't have a legal contract, but it's still a legal contract. A written contract is just something that makes it easier to prove that you have a contract and what's in the contract. But what does it mean? It means when you have a written contract, it means that it's a legal contract that can differ from the written contract. There is mandatory law that will always apply and if you have a provision in your contract that is contrary to mandatory law, it will be invalid. It may not be executed.

Also, if both parties agree and they can prove that they agree on something, but they put it incorrectly in the contract, it will still be as they agreed on. There's a Latin saying in contract law, (speaking Latin).

If you declare wrongly, it doesn't matter, the contract is agreed on what the parties have agreed on.

So what does it mean for a code bit contract? It means that the legal interpretation might differ from the execution of the code.

So to answer the question, code can be law but the contract can still be different than the execution of the code.

Code is law, except when it isn't.


Second thing, automatic execution of a contract. We all know vending machines. Vending machines are like automatic execution and even conclusion of contracts. You select something, and then you get the chocolate. Would you buy a diamond out of these vending machines? Put in 1,000 Euros and hope that the diamond will drop? And maybe it's stuck. Maybe it's wrongly programs and you won't get a diamond. Probably not.

So the vending machine is in the sole control of one party. You cannot see the code and the parties can always exchange the code to something else. You cannot trust a vending machine. Of course, for some chocolate, you don't care. It's not a huge risk. But for other transactions, you do care.

There is no secure logging, no proof, and that's the reason why I say if it's just automatically executed, I wouldn't call it a smart contract, but there are people who do.

But this is the second aspect of automatic execution, but you see because this lack of security, there's something that provides us trust and to give you another example, some years ago, Amazon was introducing the kindle reader, and people had "1984" on the kindle reader. And later on Amazon had some legal issues and they removed "1984", the book from the Kindle reader of the customers, which means there is some automated system and they can just change the rules, and that's what we don't want.

That's the reason why we use blockchains there because it's immutable. It means you have a ledger that cannot be changed, just by one party.

And what are smart contracts in the programming sense? It's a programmable blockchain. So when we got this chocolate game, we had specific rules like when you do a transaction, the person who is receiving the transaction cannot get more chocolate than the person who is sending the transaction being of course, otherwise you create money by it. Those are some kind of basic rules. And you can have more complicated, more sophisticated rules and put it into your own coding, and you don't have to create a special blockchain for it, but you can just use a program of the blockchain, for example.

In a way, with a blockchain, that's fixed, it's like a law. And a blockchain where you can define your own rules concerning, of course, only your universe, it's like a contract where you also can define your own rules. So this is blockchain inside the smart contracts. It's where you can define any kind of transaction rules within a blockchain setting.

The advantage of a smart contract on a blockchain is that it's started on a blockchain. It's executed on a blockchain and it's mainly secure against manipulation. So you can just say, well, one party changes it.

If there is a possibility to change it, it has to be in the contract before, and you can't just include it later on. So the rules are there and the rules are kept.

Then smart contracts can act on cryptocurrency. Our vending machine, they can act on money. You can insert money. It can accept money. It can keep money. It can give you back some money. So the vending machine has the power on some cash. So smart contracts on a blockchain, they have the power to act on the cryptocurrency and also, of course, on the ledger. So this is their domain. And if you have a smart contract that cannot act on any currency, then, of course, it's largely reduced because then the smart contract just states something, but cannot execute it.

So smart contracts are small strips on a blockchain that can be legal contracts, but even if they are, it doesn't mean that one smart contract is one legal contract. A smart contract can be used to do a series of legal contracts and also the creator of the smart contract is not necessarily the party of the legal contract. So there is a connection, smart contracts can have something to do with legal contracts. They don't have to, but it's not one-to-one.

To give you one example, let's say we have a seller who has a bicycle, and wants to sell this bicycle and, of course, we want to sell it by a smart contract, like an eBay implemented as a smart contract. So we have a blockchain and we have someone who programmed a smart contract, a smart contract developer. And the smart contract developer puts the smart contract there, and the seller sends a message to the smart contract.

I want to sell a bike for 4 esa or whatever currency there is. The description of the bike and, of course, in the contract itself, well, there's no buyer yet and it's not paid and not delivered. Then, of course, there is somebody interested, looking for a bicycle, and he sees the offer and says, well, I want this bicycle.

What he does is he sends an acceptance so there's a contract made and already sent the money, but the money is stored on the smart contract. So it's not directly sent to the seller, but the smart contract keeps track of it and if the seller does not send the bicycle, the buyer can get his money back.

Then, of course there's the delivery, and the seller goes to the post office and the post office. Bring the bicycle to the buyer. And they will send delivery confirmation to the smart contract and with this delivery confirmation, the smart contract will transfer the money to the seller.

Why did I use the Russian post? To illustrate two things. One thing the Russian post says they want to do the tracking via blockchain and the second thing is smart contracts lets you gain some trust but still you have to trust in somebody. You have to trust in the post that the confirmation is correct.

And, of course, you have to trust that there is a bicycle that works in the box that is given to you. Because they will not confirm that you received a bicycle. The post will confirm that you received the paper box, the card box.

So what are the impacts of smart contracts? Where are they used?

Yes, please.

(Off microphone comment)

>> PARTICIPANT: To the previous part of the contract, so the smart contract has another contract with the post office because they have to ensure that that was a bike which he sent, or the seller has to take the money back, if the bike -- if that thing wasn't a bike.

>> JÖRN ERBGUTH: Well, the post office is just what we call an Oracle. So the post office is just sending -- just giving some information to the smart contract on the blockchain.

>> PARTICIPANT: So it's a part of the smart contract?


>> PARTICIPANT: There is a line for the post office in that contract?

>> JÖRN ERBGUTH: Exactly.

>> PARTICIPANT: So ensure what was being sold was a bike?


>> PARTICIPANT: Because the problem is I order a bike and it comes a raccoon and what am I supposed to do with a raccoon rather than a bike?

>> JÖRN ERBGUTH: Well, this is exactly part of the problem that you can have more insurance, more security, but you will not have complete security. And even if the post confirms that it's a bicycle, it doesn't mean that it has to be a working bicycle. Maybe it's defective.

So you always have some issues that remain.

>> PARTICIPANT: So you cannot send it back because the money has already been sent to the one who told it? So I'm getting stuck with a bike and it doesn't function or it's not even a bike?

>> JÖRN ERBGUTH: Sure. That's a problem when you buy something from somebody remotely. It will not solve all problems. It will solve some --

>> PARTICIPANT: We don't have any insurance of what happened if this transaction is real that means?

>> JÖRN ERBGUTH: You have some additional insurance that you will receive something by the post office. Yeah.

>> WALID AL-SAQAF: Just to illustrate this example is maybe not the best in understanding how smart contracts natively work but they have the combination of physical material with crypto material but the ambition of Nakamoto, they need to communicate exclusively within this ecosystem and some way of thinking of the smart contracts is multisig in bitcoin. Bitcoin has its own language called bitcoin script. And a smart contract can be something like an address that you send to and this address has information saying only release this amount if two people sign the transaction.

So in this case, it's exclusively in this ecosystem. It means that two individuals who have wallets, sign the transaction, and then it's sent to that common smart contract, and then it's sent to a third wallet. There's no outside interference. I like the fact that you step beyond this, and go back to the original human error prone world and that's why it's not complete.

>> PARTICIPANT: I know that through transaction, I will use the smart contract -- sorry. I know that through real transaction, I would use the smart contract but I wouldn't use it for this transaction, actually, because you are not ensuring me what I'm getting anyway.

>> JÖRN ERBGUTH: If you buy something on eBay, it's the same thing.

But you have eBay that ensures or PayPal that ensures some transaction. As Walid said, if it's purely on the blockchain, or if it's some right that you purchased or if it's about something that's noted on the ledger, then you can have complete insurance and security.

But, of course, always if you touch the real world, you have real actors and you need -- and you need to trust somebody again.

>> PARTICIPANT: Can I ask. Thank you very much. It was very interesting but still I have a question related to the -- you said that you can change the smart contract if it's written in the contract. And how it's possible, because when you have -- when we have proof of work, like I get something, and then this is a hashed and this is kind of very secured, and how it's possible to change it, and what is that?

>> JÖRN ERBGUTH: Well, I have still some slides with some problems but I can answer this question right away.

It is not possible to change a smart contract, but, of course, a smart contract can have some provisions that you can have a new smart contract that's connected to the old one and will kind of -- the transactions will be deviated to the new one. So you can have a provision in the smart contract --

(Off microphone comments)

>> JÖRN ERBGUTH: No, the original information was saved, but you can have a bait and switch into the smart contract that you can with the proper authority that is defined in the smart contract add a new provision to the smart contract.

(Off microphone comment)

>> PARTICIPANT: So what transaction will it be? Any example of --

>> JÖRN ERBGUTH: Well, any kind of update of the rules and this is -- this is one very important aspects. Even the best program, I cannot produce a smart contract that's perfect. And even if the smart contract would be perfect, the outside world changes and you might need to adapt the smart contract.

And if you need no do that, then the question is how do you do it?

If you give this power to some central authority, or the value of the smart contract is again, because you then have a central authority that will decide.

So this kind of governance needs to be done in a decentralized way like the mining is do in a decentralized way so you can ensure that this power, when needed is not abused.

>> PARTICIPANT: Can I ask -- over here.


>> PARTICIPANT: So example is pretty interesting, all right. What was interesting was the role of the Oracle. So the whole point -- well, correct me if I'm making a mistake, the whole point of an Oracle is to stabilize the ecosystem? What pulse is doing, it's offline. It's doing an operation in the real world. It's confirming that it got the bike and confirming that it delivered the bike. So is this the role that Oracles do?

>> JÖRN ERBGUTH: Yes, the Oracles take some -- they take some outside information to the blockchain. Because the blockchain has no eyes and ears.

Let me give you some example. One example, where smart contracts are used, in initial coin offerings, this is an internal offering, meaning don't have to thrust somebody, but the transaction is completely on the blockchain. And this is the way that most start-ups in the blockchain domain are currently financed and the billions being transferred this way.

Then you get, of course, the bitcoin transactions that this intermediate banks. So you can make a transaction. You don't need a bank in between. And we get with the shared economy, we have a lot of intermediaries. New intermediaries.

They don't provide a service, but just the connection between 9 provider and the consumer of a service. And all of those intermediaries could be potentially -- there's a large discussion whether it will really happen or not, removed by smart contracts because smart contracts are acting as an intermediary between parties, but as a peer-to-peer intermediary.

But, of course, there are open questions. There are open questions concerning regulation, concerning governance, as I said.

Let me just finish this slide and then maybe you can get a macro ready.

Government of the autonomous, if you say the bike is defective and somebody else says no, it's okay. It attracts criminal business because criminalists need trust. They can't go to court because another criminal didn't deliver. So they need something that provides trust to them, and that's the reason why it's attractive to criminals.

And there's an issue of privacy. Data is public on the blockchain. And there's issues that we already discussed, like fees, energy consumption and scalability.

Your question, please.

>> PARTICIPANT: Yes thank you. I have a question regarding identification. And, of course, with the bicycle example, how do I as the customer or the buyer verify that I received this bicycle? I need then to identify myself in some way towards the smart contract and the blockchain. I'm wondering, is that done? If it's not, is it something that's needed? Because there is a big debate about blockchain being, well, very transparent and anonymous.

So I would like you to say a few words about identification.

>> JÖRN ERBGUTH: There are two levels one is the identification on the blockchain. It's usually done by private keys. So to be owner of an account, the account has a public key. So this public key can be used to send money to -- cryptomoney to it or to do a transaction with it.

And if you want to authenticate yourself, you use your private key that corresponds to the public key. And the private key needs to be private and you sign the transaction with it, and with the public key, you can verify that the transaction has been signed with the private key.

Of course, this kind of private key has a lot of risks because if you lose it, you can't prove anything. If somebody gets hold of it, you are in trouble as well.

>> PARTICIPANT: So there's no way to identify yourselves towards the keys that you own?

>> JÖRN ERBGUTH: Yes, well, this is the identification of -- on the blockchain. Then if you go to cryptocurrencies, we have a lot of discussions about KYC, MYL, and the anti-money laundering thing. Then we don't want just to have a crypto authentication of somebody holding an account, but we want to have the personal identification.

And then there is, of course, debate, how should this be done and what is the role of the governments of banks, of intermediaries who identify the identity.

>> ARVIN KAMBERI: We only have five more minutes.

>> JÖRN ERBGUTH: Yes, but we can continue the discussion, I think.

>> PARTICIPANT: So may I ask something, because I'm not completely, you know, sure clear, about what you just explained.

Doesn't exist real money. I am not -- I have a key. I'm holder of a key, which I'm part of this -- of this trance actions. So I'm transferring you what actually? What is my currency?

>> JÖRN ERBGUTH: Cryptocurrency.

>> PARTICIPANT: How I bought this currency? Where am I supposed to buy it?

>> JÖRN ERBGUTH: You can buy it from somebody else who is -- who has --

>> PARTICIPANT: So I have to work with the miners?

>> JÖRN ERBGUTH: Not necessarily miners. But I know you, you got this chocolate. You got this cryptocurrency. So I say, well, will you sell me some of them?

And then I give you some dollars or some Euros for it. And so --

>> PARTICIPANT: No, wait.

>> JÖRN ERBGUTH: This is an exchange.

>> PARTICIPANT: It cannot be online because I have to give him real money afterwards.

>> JÖRN ERBGUTH: But, of course, there's an exchange where the currency, real money is traded against cryptocurrency. Maybe we have a lot of other questions? Yeah?

>> PARTICIPANT: Yeah, so the way that any friend does, it he does work in -- he basically makes his entire living from cryptocurrency exchange. He connects with people. Let's say he has bitcoin that he wants to sell. He connects with people who want to buy bitcoin and in this case, generally speaking, he meets with them in person. They give him a cash transaction. And then --

>> PARTICIPANT: He physically gives him money.

>> PARTICIPANT: They physically gives them money and he then sends them to their -- to their online wallet, the amount of bitcoin that they bought them --

>> PARTICIPANT: I give him money and I didn't get anything back!

>> PARTICIPANT: You got bitcoin. And then I go home and do it when you can do it.

>> JÖRN ERBGUTH: You get a question, please.

>> PARTICIPANT: On a slightly different element of this, how -- I mean, considering that as we have somewhat seen, the vast majority of people will not likely understand bitcoin or cryptocurrencies in general, and will need to do it through either in the middle man or just see it as something like eBay. How is this to have an escrow account function for a vast majority of people?

>> ARVIN KAMBERI: May I add for the previous explanation for this?

(Off microphone comments.)

>> ARVIN KAMBERI: When you have this and crypto together, you can buy it for the dollars. You can gain crypto. You can work for crypto. You can, like, give your services online, being paid by bitcoin or anything else.

>> PARTICIPANT: I want -- I'm a new client. I want to get this crypto and bitcoins. I don't know how to get it.

>> ARVIN KAMBERI: Right now there are three ways. You can mine them, as we saw it. You can buy them for a fee, by a fee, it means dollars, Euros, et cetera, or the third option is to be paid in bitcoin, for a seller, for example, your employee gives you like ten bitcoins for your payday. So that's the three ways how you can actually acquire them right now. You can mine them. You can buy them or in exchanges everywhere else, and you can Sen them instead of money.

>> PARTICIPANT: It needs a lot of trust to get into this, don't you think?

>> ARVIN KAMBERI: Go ahead.

>> JÖRN ERBGUTH: So, of course -- well, you spend money for cryptocurrency, and you have no guarantees that cryptocurrency is worth anything, but if you think twice, do you have a guarantee with current currency? Is there a guarantee that one Euro will buy you chocolate tomorrow? There's a high probability.

>> PARTICIPANT: There is inflation but at least it will buy me something. Or there will not exist any money anymore. So that's the solution.

>> JÖRN ERBGUTH: But, of course, this is part of the cryptocurrencies. As the system really guarantees you that nobody can just create inflation.

So it's not possible to create a number of bitcoins tomorrow, but the system does not guarantee you that anybody will give you anything for them tomorrow.

>> ARVIN KAMBERI: Can I -- we need to work -- well, I will give a case. For example, you pay 10 Euro for this crypto chocolate, would it encourage you to pay 10 Euros if you know there is someone over there who will definitely 100% pay you back your ten Euros for this crypto chocolate?

Will that be a solution? Are.

>> PARTICIPANT: You give -- I buy this chocolate.

>> PARTICIPANT: You pay -- imagine crypto chocolate. Well, there's a problem of trust, why should you trust this crypto chocolate.

>> PARTICIPANT: That exists.

>> PARTICIPANT: That exists or maybe somebody is lying to you. What if there is someone who will pay you back any time when you wish it for, if you deliver to him your crypto chocolate, he will pay back ten Euros.

>> PARTICIPANT: No, there's no point for me to buy it because I don't have any interest and at least it would be 11.

>> PARTICIPANT: That's another side.

>> JÖRN ERBGUTH: Okay. Thank you.

>> ARVIN KAMBERI: Thank you. We will have to finish this up. People are hungry and it's lunchtime. So -- so just one more notion. Please, I want you to follow the session in the garden after the lunch, it will be at garden.

>> JÖRN ERBGUTH: It's at 4:15.

>> ARVIN KAMBERI: You move the slot?

>> JÖRN ERBGUTH: No, it's 4:15.

>> ARVIN KAMBERI: Thank you very much. Have a great day.

(End of session)

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