CRYPTOTASK - Decentralized Task Market


We advocate a decentralized challenge market based totally on blockchain era that disrupts modern day freelancing structures. The foundation is a consensus mechanism much like that utilized in current prediction market initiatives consisting of Augur and Gnosis, with some essential differences and improvements that allow scalability, an trouble plaguing most of the popular blockchain tasks. One key innovation is a reviewer board choice mechanism built into the blockchain, together with an escalation option that satisfies Nash equilibrium. The choice mechanism satisfies the circumstance of secrecy that allows you to discourage potential collusion and off-chain conversation among reviewers by implementing a reporting mechanism. Voting is achieved in  stages, together with a mystery dedicate segment, to dissuade events from the use of the ready strategy.



Bitcoin regarded in 2009 and commenced the blockchain revolution, decentralizing simple finance. Soon, other initiatives accompanied, with the principle idea of decentralizing more than simply the monetary device. That culminated with Ethereum that is a decentralized Turing whole machine, that theoretically lets in different projects to put into effect their good judgment at the Ethereum platform, in place of constructing a brand new blockchain from scratch. However, scalability stays the primary trouble. Considering Ethereum is not proof-of-stake (PoS) and does not aid sharding yet, any larger amount of calculation receives very expensive. Additionally, Ethereum gas fees are unpredictable, as other tasks compete for computation time at the identical platform. Thus, building on top of Ethereum for us isn't possible, considering the computational load of the reviewer mission mechanism and different strategies.

Untapped freelancing marketplace

We endorse making use of the blockchain technology to the contemporary freelancing market. The business potential is massive, with freelancers making up 35% of the body of workers in the U.S. And contributing approximately 1 trillion USD to the financial system. The decentralization that blockchain allows gives multiple benefits: decrease costs, no censorship, dispute system transparency, no financial limits, no arbitrary meddling from companies or governments.

Comparison to prediction markets and other relevant initiatives

Prediction market initiatives primarily based on blockchain are the most relevant to the proposed device. These markets are created for the purpose of trading the outcome of occasions and may be used as oracles as nicely.

The motive for relevancy is that prediction markets' occasion decision method is based on a consensus mechanism just like the one proposed here. It is, however, easier to design the proposed system robustly than a preferred prediction market, as the fee of every mission is described earlier, not like with prediction markets where the value of the final results changes over time as traders region bets. Also, on assignment vs event basis, venture markets scale extra without problems as assessment procedures are prompted simplest in case of disputes; this is to say for most instances the venture author and freelancer will agree at the mission end result and price with out the need for arbitration, even as prediction markets usually require an oracle.

Additionally, unlike prediction markets, parasite attacks are not a situation, as the system serves the
purpose of settling potential celebration disputes, so there's no public result really worth stealing.

For example, a potential Truth coin marketplace assault would require a good sized stake of voting coin, but the assault sales is almost limitless. There is likewise a parameter tau, associated with the charge of selection-slots, complicating decision of occasions inside the far future. Overall, the system is complicated, and there may be presently no implementation.

Prediction market does no longer have a dispute mechanism properly-defined inside the original white paper, but latest blog posts  advise a hierarchical escalation mechanism just like the one we recommend. It is uncertain how the reporting positions are crammed and whether it is known earlier who the journalists are. That is critical due to the fact if newshounds understand who the alternative journalists are, they can communicate previous to vote casting. From a sport concept perspective it may be argued that this is irrelevant because the escalation mechanism ensures that any collusion could be irrational. However, mainly within the mission market case, there are reasons why it's miles higher to avoid the opportunity of reviewer verbal exchange, together with: duties finished, but nice is poor, reviewers higher up are not as skilled inside the venture area as specialised reviewers are, and many others. Augur is carried out on Ethereum, and for that reason will have severe usability and scalability issues considering the modern-day nation of Ethereum platform.

Gnosis is some other Ethereum-based prediction market, that is probably to use the “Ultimate oracle”
scheme. The concept is that a set guess is placed on an final results (say a hundred ETH), after which any holder can assignment the decision by placing a bigger guess. We propose using a similar system for dispute resolution, however, handiest as the very last step inside the hierarchical dispute decision, and not with a fixed preliminary deposit, but associated with the disputed task fee. While, theoretically, the remaining oracle can be the handiest dispute mechanism, there are blessings to having first randomly decided on reviewer panels, which includes: better knowledge of the venture area, no time bias (reviewers can not see what others voted for) and additionally, any larger quantity for the preliminary deposit might be out of reach for the ordinary gadget customers. On the opposite hand, reviewers are specialists retaining reasonable coin stake, and they're in a higher function to increase the dispute than the common freelancer. The reasons for having a dispute hierarchy are much like those for having a hierarchy in classical criminal systems, and why there is not handiest the superb court.

Stox is but every other proposed Ethereum-primarily based prediction marketplace, with dispute architecture not yet defined.

Block lancer is the most effective blockchain task/freelancing marketplace undertaking that we are aware about. The dispute mechanism is fundamental, requiring all stake holders to vote on all disputes, for that reason it's far hard to achieve scalability. It is also Ethereum primarily based, which in addition limits scalability, but it will be interesting to see how it develops once Ethereum implements PoS and sharding.

Though some principles are shared inside the aforementioned initiatives and the proposed machine, none provide a satisfying answer for our goal. Thus, we decided to design a specialised blockchain on the way to put in force all required mechanisms efficaciously, offering more scalability without relying on 1/3 party structures inclusive of Ethereum.



We introduce a blockchain-based totally project marketplace machine such as clients, freelancers and reviewers. Clients submit activity gives, freelancers apply for these and reviewers are stake-holders that placed down a deposit, as a minimum same to the price of tasks they intend to be reviewers for, and define their location of understanding; within the case of a task dispute for which they were selected into the evaluation panel, they are required to solid a vote on whether or not the mission was completed or no longer. Reviewers will need to define their areas of information actually, in any other case they threat dropping in the consensus mechanism. Reviewers get a percentage of each venture price although no dispute process is initiated, and if a dispute is initiated, they get a larger percent as repayment. Also, all Task Coin holders get a small percentage as a dividend. In the simplest case, the client and the freelancer will agree on the process outcome. If the task is finished, the freelancer receives paid, and if it isn't always completed or the deadline expired, the patron gets a refund and the freelancer's deposit. Clients placed a deposit equal to the challenge cost, whilst freelancers need to place down 10% of the venture they implemented for. The freelancer deposit is used as a measure in opposition to wasting the customer's time, as without it, freelancers ought to essentially DOS the system. It is also used to initiate disputes, because it can be paid to reviewers as compensation. In case of a dispute, depending at the result, either the freelancer or the purchaser will lose 10% of the task cost, with a view to visit the reviewers.

Also, 10% of every reviewer's deposit who voted in opposition to the consensus or did no longer cast the vote, is distributed among other reviewers inside the panel. Otherwise, if disputes were sufficiently rare, it could be affordable for reviewers to disregard their responsibility in case of a dispute, and just accumulate the charges from tasks that were no longer disputed.

Review panels are created for each dispute and consist of randomly decided on reviewers. There are 10 reviewers on average within the panel, even though that range isn't deterministic. Reviewers aren't privy to different reviewers. Voting is executed in  tiers: commit and screen; the idea being that no reviewer can wait to peer how other reviewers voted. The proposed device satisfies Nash equilibrium as no birthday celebration has incentive to change their recreation method, considering that other events maintain their techniques constant.

The device blockchain is a Monero fork, as ring signatures hide the sending cope with, making the venture writer unknown, in addition to reviewers when applying for the panel after getting to know that they have been decided on. The reviewer selection mechanism is built into the blockchain; it could be notion of as a tough-coded clever contract.

The device does no longer rely on recognition to assure truthful challenge evaluation. While reputation may be used as part of the undertaking applicant choice method on the venture writer's part, it is not a important factor that ensures machine soundness. Systems counting on recognition, among different complexities, which include potential Sybil assaults, face the problem of initial reputation. That is, a system can be unstable if there are no individuals with set up reputation. On the other hand, giving a few preliminary recognition to decided on customers may be arbitrary and goes towards the decentralized philosophy.

In Figure 1 the machine overview is given. There is a number of undertaking domains, and each reviewer can apply for one or greater domains. In case that the freelancer and the patron cannot agree on the venture submission, a dispute manner may be initiated by both celebration. A evaluation panel is shaped such as 10 reviewers on common, R1 to R10. S_ri is the ith reviewer's non-public key. Hash(n+d) is (n+d)_block's hash.

Each reviewer computes a value on (n+d)_block's hash with their non-public key: RSA(hash(n+d), s_ri).

A certain range of starting bits defines the mission wide variety (in case that a couple of dispute changed into initiated in that block), even as the ending bits are used to decide whether the reviewer become decided on.

The probability of being selected is proportional to the reviewer's stake. It is critical to be aware that at this level best every reviewer knows this data for themselves, however can prove it to anyone later
via revealing the acquired cost that every person can later use with that reviewer's public key to check that the very last price is equal to the (n+d)_block's hash. After the evaluation panel has reached its decision, either the client, the freelancer or any member of the overview panel can dispute that decision and amplify to the “Ultimate oracle” which include all the stakeholders.

Dispute system and reviewer panel selection

As the dispute mechanism is a important system thing, we will cross into more element.

At every block, each reviewer encrypts the ultimate block hash with his personal key, and if the remaining element is smaller than his reviewer stake percentage, he is aware of that he's selected. The important concept here is that simplest he is aware of that reality. That can later be demonstrated to every body with out revealing the personal key, genuinely by means of giving the encrypted price, while all and sundry can encrypt it with the matching public key, for this reason checking that the acquired variety suits the authentic variety, that is the original block hash. The reviewer then proceeds to publish the vote hash, and then inside the screen segment he proves that he become selected and well known shows the vote. If there are extra disputes, the starting part of the encrypted ultimate block's hash may be divided into undertaking ranges.

Any celebration that attempts to talk off-chain may be punished by using each person the usage of the breach mechanism, ensuing within the offending birthday celebration's loss of deposit. For example, any try through a specific reviewer to provide proof-of-selection as the first step towards collusion may be stated as breach.

The end result given by means of the assessment panel may be challenged via either the freelancer, the client or one of the reviewers with the deposit equaling the mission cost. The better example can either be another evaluate panel or a mechanism much like Gnosis “Ultimate oracle” which includes all the coin stake holders.

The challenge answer is submitted publicly, however the encryption mechanism can be delivered in order that best the purchaser can see the solution and is found out simplest in case of a dispute. The client generates a one time public-personal key pair and announces his one time public key that the freelancer uses to encrypt the answer. In case of a dispute, the consumer well know shows his one time private key.

Potential assaults

Let us take into account a dispute and the chance of an attacker getting more than 50% of overview panel slots, depending on the whole evaluate stake he holds.

N is the wide variety of reviewer positions the attacker holds, m is the quantity of reviewer positions honest reviewers hold (total - n), at the same time as p is 10 divided via the overall number of reviewers, because the device selects a evaluation panel with 10 contributors on average.

The opportunity of an attacker getting i slots is then given via the binomial distribution:


We present a singular system that solves scalability troubles found in cutting-edge prediction markets and freelancing systems, letting us target the economic freelancing economy, offering some of blessings along with decrease costs, no censorship and other blockchain associated benefits. Considering the size of the freelancing financial system, the industrial potential is huge.

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