Online lists are increasingly being utilized for various purposes like ranking and organizing information. The lists might comprise of top destinations, best schemes to invest, top universities or even tokens. However, there are several persistent issues with centralized lists. The advent of blockchain technology has resolved several persisting technological issues. One such application is that of Token Curated Registries, the brainchild of Mike Golden.
On a centralized list, the list viewers have no other option than to believe in the credibility of the list. One can remove the list’s members arbitrarily and also tamper the ranking methods by paying some fees.
Decentralized lists often fall prey to spam and fraudulent voting. Thus, to sustain the quality, semi-centralized list moderators are appointed.
The first implementation of a TCR system was launched on the Ethereum mainnet. In a token curated registry, there is no need for a centralized list owner. Moreover, there are economic incentives for decentralized list curation.
For example. There is a list of” Best Restaurants.” In this list, each list entry contains the restaurant name a website address and the corresponding address. Each list has a native token that anyone can purchase. For applying to the list, an applicant needs to buy the token and place an application deposit. The token holders can also challenge the application if they feel that the application doesn’t belong to the list.
Voting in TCR
When initiating a challenge, token holders may vote to accept or reject the application. The vote is proportional to the number of tokens they own. If in case the majority rejects the application, the deposits are distributed between the challenger and the token holders ( those who voted against the application).
On the other hand if the majority accepts the application, data is put on the list. Additionally, the applicant gets to keep the deposit. The challenger’s deposit is thus retained and split between the applicant and token holders who voted in favor of the application.
Parameters Related to Token Curated Registries
The minimum number of tokens a candidate must lock as the deposit for their application, and for the duration of the listing.
The time during which an application can be challenged.
The duration which token holders can vote for a particular challenge.
The duration in which token holders can reveal committed votes for a particular challenge.
The percentage of the retained deposit acquired by the winning party.
It is the percentage of tokens revealed in favor of keeping a challenged candidate necessary for that candidate to get the listee status.
Possible Attacks against Token-Curated Registries and Preventive Measures
There are many potential attacks against TCR’s and they include-
A registry can degrade its quality once it gains entry in a registry, this is known as registry poisoning. A rational token holder will, however, discover such behavior and subsequently issue challenges. Thus, the listing needs to forfeit its initial deposit, and it would damage its reputation.
Coin flipping and vote Memeing
As there are no penalties for making bad decisions in voting, token holders might “ flip coins” on their votes, then make sober assessments of the issues at stake. However, An even distribution of votes from coin-flippers and a minority of activist token holders can thus rationalize the process.
A TCR can also fall prey to” vote memeing,” it becomes a trend to vote in a way for always being in the majority voting block. In this case, a minority of token holders cannot bring rationality.
A troll for any random reason would want to add a “ bad” listing to a “ good” registry. These attacks are ineffective in the case of a well-maintained registry. It would lead to the troll losing its deposit when a rational token holder issues a successful challenge.
The registry might be prone to a 51% attack ( a powerful entity spending a significant amount of capital and purchasing a challenge-proof majority and thus populating the registry with low- quality listings). A prominent concern is the prevention of such attacks as only a minority of token holders are likely to be actively voting at any given time.
Different types of Token Curated Registries
1. Unordered TCR
An unordered TCR is a simple list where voters can vote on the items they want to include.
2. Ordered TCR
The ordered TCR adds an index to each list. These lists can serve as ranks, queues or instruction sets.
3. Graded TCR
In a graded TCR each list does not need to occupy an index. Each list contains its own mutually exclusive rank in form of some points.
4. Layered TCR
Any listing will make the first registry follow some criteria. In a layered TCR, if a list needs to promoted to the next layer, it will be calculated on the following metrics-
- Time spent in the previous layer
- Value-added actions performed
The listing lives only 1 layer at a time.
Startups utilizing Token Curated Registries
MetaX is creating an Ethereum-based blockchain called adChain. This blockchain allows advertisers to find trustworthy publishers and provides parties with a platform for tracking advertising impressions.
The first protocol under development for adChain is a TCR which lists trustworthy, non-fraudulent publishers for advertisers to place their ads.
The quality of the registry will not be verified by MetaX in any manner. The publishers will manage the registry by following the conventions of the TCR.
District0x incorporates TCRs in the form of the District Registry. The token holders accredit the district which is part of the District Registry.
Ocean Protocol is an ecosystem for sharing data and associated services. With Ocean, consumers and providers will be able to buy and sell data that could be used in autonomous vehicles, medical research or other applications which require large amounts of data.
In the Ocean Protocol, there is a provision for risk-staking, where prospective members can have current members vouch for them. Under this setup, a current member puts their token deposit at risk on behalf of the new member. In return, the current member gets a share of some of the token earnings from the new member.
The use of token-curated registries has increased rapidly since its initial conceptualization. More importantly, with the launch of many new crypto networks in 2018 incorporating TCRs, their future looks bright.