Kleros –Cryptoverse AMA

7 min readMay 28, 2020

25th May 2020

Guest — Clement Lesaege (Co-Founder, CTO)

Q : What do I need to do to become a juror? How do jurors make money from Kleros?

A : Jurors need to have the skills required to solve the dispute of the court they choose.

Some courts are quite general and everybody could solve the disputes of those courts.

Some courts require specialized skills (like the Blockchain->Technical one).

Jurors need to stake PNK in order to be chosen.

Jurors voting coherently (same as the final result) are paid arbitration fees in ETH.

Q: There are many types of Disputes that are Judged in Traditional courts like #Criminal_Cases & #Civil Cases, At Kleros platform What type of Cases can be resolved?

A: Kleros target market is quite different from the one of state courts.

Kleros is an opt-in system, this means that people have to choose Kleros as the arbitrator of their contract (so no criminal cases where parties do not have a prior contract).This can be done explicitly by users or by using a dapp having Kleros as it’s arbitrator.

The 3 main cases are:

- Escrow disputes: You can make a payment for a good or service, the money will be locked in the escrow contract until the good or service is provided. If everything goes well, the buyer can unlock the money. If the there is a dispute about whether or not the good/service was provided, Kleros jurors can rule on it and the money in the contract will be transfered to the winning party.

- Oracle disputes: Some dapps requires to get information about the outside world (for example did an earthquake happen in an insurance dapp) and perform actions depending to the result (ex pay insurance). People make make conflicting reports and Kleros can solve the dispute about which report is correct. We can also think of price oracles in this category.

- Curated list disputes: Here the goal is to determine whether or not a item belongs to a list. For example “Are the information about this token correct?”, “Does this forum post violate the forum rules?” “Is this hotel listing legit?”.

Q: Kleros will soon launch “CURATE” Can you explain What is “CURATE” and its potential to change the entire internet?

A: Curate see https://curate.kleros.io/, is a dapp allowing people to make curated lists (TCR). It allows creating them really easily from a graphical user interface.

Curated lists are everywhere (lists of items in ecommerce platforms, list of hotels in travel websites, exchanges listed on coinmarketcap, blog articles).

Traditionally, those has been curated by people owning those website, curate allows to have the same results but for decentralized apps.

By removing the need of editors we can allow new forms of dapps to be created, think decentralized publishing platforms (not showing fake news), uncensorable filesharing networks (need to verify the files are correct and not viruses), decentralized versions of Twitter, etc…

Basically it’s a decentralized moderator.

Q: If in some opportunity, a Juror does vote randomly, would he or she get penalized?

A: Yes, Kleros is a staking system and jurors need to stake PNK to get a chance of being drawn.

If you are drawn and don’t vote coherently with the final result, you will lose some of your staked PNK. If you vote randomly, you may vote for the final result or not. But you are less likely to vote for the final result than if you had done your work properly.

So by voting randomly, you increase your chance of being incoherent, thus of losing tokens. So jurors voting randomly are penalized from a statistical perspective.

Q: Trust and Security are the most important things in cryptocurrency. Why should people feel safe with Kleros?

A: There are 2 kinds of security problematic, the cryptoeconomic one (making sure jurors will vote honestly) and the smart contract one (making sure Kleros contracts won’t be broken).

For the cryptoeconomic one, we have designed incentives such that jurors should be rewarded when doing their job well and penalized if trying to abuse the system. We did look at it from both a theoretical perspective and a experimental one. We did try some cryptoeconomic attacks in the Doges on Trial experience but were unsucceful breaking the system. We also put some bounty offering high amount of ETH whomever would manage to give wrong rulings and the bounty wasn’t claimed.

From a smart contract perspective, we make sure to make short and simple smart contracts.

We spend more time reviewing and trying to catch bugs in contracts than we spend time writing those.

We also set up some bounty programs paying hackers managing to break contracts (before they are put in production). We did reward hackers for more than 100 ETH of bounties. Note that those bounties were part of the development process, no contract were ever broken on mainnet.

Q: Does Kleros Have any Partnerships with private Enterprises or Govt. institutions?

A: “Does Kleros Have any Partnerships with private Enterprises or Govt. institutions?”

Yes, we are incubated by Thomson Reuters. We also got some grant from the BPI (French Public Bank) developing the Themis project (https://blog.kleros.io/french-bank-grants-subsidy-to-kleros/) made to ease the integration of Kleros in dapps and businesses.

The Blockchain Dispute Resolution Layer


Kleros Receives BPI France Innovation Grant

The Banque Publique d’Investissement (BPI) of France has awarded Coopérative Kleros a prize for the launch of Project Themis.

Q: Why use PNK instead of ETH?

A: First of all, I’d like to emphasize that PNK is only required for staking as a juror, arbitration fees are paid in ETH. We need PNK to protect the system against 51% attacks.

Imagine we’d use ETH instead of PNK. To 51% attack the system, you’d need to get 51% of the ETH staked in the system. You could probably buy those at price close to market price.

But now with PNK, since most of the PNK is in the system, you wouldn’t find the liquidity to buy 51% of staked PNK and even if were able too, as you buy more PNK, the price would steeply increase such that buying 51% of the PNK cost way more than 51% of the marketCap of PNK at the time you try the attack.

So PNK increase the budget (amount of money you need to have) to make an attack.

Now let’s look at how we could recover from an attack. With ETH, there isn’t any recovery possible, if you make a new system, the attacker can just move its ETH to this new system.

With PNK you can fork the token removing the balance of the attacker creating a new system with only honest holders.

So PNK provides a recovery option.

Fortunately, all of those never need to happen to protect the system, having those makes attacking the system unattractive in the first place.

Q: Can you talk about the Kleros governance mechanism? What can governance mechanisms be used for? Do token traders also make decisions about Kleros governance?

A: Yes, Kleros is a DAO, which means that the team doesn’t take or control the system.

Anyone can create some governance proposal if they want to change some part of Kleros. This can be new courts, changing the fees and parameters, new versions of Kleros, pretty much everything.

Even the team funding goes through governance and token holder validate the PNK funding of the development team.

Q: Do you see Kleros in the resolution of SPORTS disputes? In your career, was there any difficult, complicated dispute that generated controversy?

A: I don’t really see Kleros arbitrating live sport events, at least in the short term because it takes a bit of time (less than traditional courts but more than referee) for parties to argue their cases and provide evidence.

However, you could use Kleros for usecases around sport events. For example you can make a prediction market (through Omen for https://example conditional.netlify.app ) allowing people to bet on sport events (classic sports or esports).

Here Kleros can solve disputes on event reports. For the bets to resolves correctly the correct results must be reported and if people missreport results it can lead to a Kleros dispute.

If you would like to play some esport games (like age of empire, chess, etc) with crypto prizes and prediction markets using Kleros, you can look at this group:

Q: Is there some regulations Kleros follows?

A: There are generally little regulation over what alternative dispute resolution methods you can use.

If you’d like to have its results enforced (police, seizing assets, etc) you’d need to follow some rules. But here the results are automatically enforced through smart contracts.

As Kleros does not deal with criminal cases (that governments want to keep for themselves) but about small contract disputes (which are generally a burden for governments). States generally are quite positive toward alternative dispute resolution systems like Kleros.


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