Polkadot provides a naming system that allows participants to add personal information to their on-chain account and subsequently ask for verification of this information by registrars.
Setting an Identity
Users can set an identity by registering through default fields such as legal name, display name, website, Twitter handle, Riot handle, etc. along with some extra, custom fields for which they would like attestations (see Judgements).
Users must reserve funds in a bond to store their information on chain: and per each field beyond the legal name. These funds are locked, not spent - they are returned when the identity is cleared.
These amounts can also be extracted by querying constants through the Chain state constants tab on Polkadot-JS Apps.
The procedure to set and clear identities is explained in detail in this support article - How to set and clear an Identity
The Ledger app on Nano S doesn't support the extrinsic for setting identity. As a workaround, create a primary identity with an on-chain account and then using that primary identity, assign a sub-identity to the Ledger stash.
Please note the following caveat: because the fields support different formats, from raw bytes to various hashes, a UI has no way of telling how to encode a given field it encounters. The Polkadot-JS UI currently encodes the raw bytes it encounters as UTF8 strings, which makes these values readable on-screen. However, given that there are no restrictions on the values that can be placed into these fields, a different UI may interpret them as, for example, IPFS hashes or encoded bitmaps. This means any field stored as raw bytes will become unreadable by that specific UI. As field standards crystallize, things will become easier to use but for now, every custom implementation of displaying user information will likely have to make a conscious decision on the approach to take, or support multiple formats and then attempt multiple encodings until the output makes sense.
After a user injects their information on chain, they can request judgement from a registrar. Users declare a maximum fee that they are willing to pay for judgement, and registrars whose fee is below that amount can provide a judgement.
When a registrar provides judgement, they can select up to six levels of confidence in their attestation:
- Unknown: The default value, no judgement made yet.
- Reasonable: The data appears reasonable, but no in-depth checks (e.g. formal KYC process) were performed (all the currently verified identities on-chain).
- Known Good: The registrar has certified that the information is correct (this step involves verification of state issued identity documents, and at the moment no account has known good identity, with the exception of registrars).
- Out of Date: The information used to be good, but is now out of date.
- Low Quality: The information is low quality or imprecise, but can be fixed with an update.
- Erroneous: The information is erroneous and may indicate malicious intent.
A seventh state, "fee paid", is for when a user has requested judgement and it is in progress. Information that is in this state or "erroneous" is "sticky" and cannot be modified; it can only be removed by the complete removal of the identity.
Registrars gain trust by performing proper due diligence and would presumably be replaced for issuing faulty judgments.
To be judged after submitting your identity information, go to the
Extrinsics tab in the Polkadot-JS UI and select the
identity pallet, then
requestJudgement. For the
reg_index put the index of the registrar you
want to be judged by, and for the
max_fee put the maximum you're willing to pay for these
If you don't know which registrar to pick, first check the available registrars by going to
Chain State tab in the Polkadot-JS UI and selecting
identity.registrars() to get the full list.
The procedure to request and cancel identity judgments is explained in detail in this support article
on-chain identity through the Web3 Foundation Registrar (i.e. Registrar #0) you will need to complete a few additional tasks. For more information visit this support article.
The set identity calls go on-chain. Hence, the contact information is available publicly, for both legitimate entities, like registrars or validators, but also scammers who might impersonate them. The strings in the identity fields are good candidates for homograph attacks, as someone could list a fraudulent website (web3.f0undation instead of web3.foundation for example) and still get verified by the registrar (if the checks are automated)!
In a decentralized network, one should be cautious making transactions with accounts solely based on their identity. If an account on-chain claims to be of Web3 Foundation, it is wise to verify its authenticity by checking directly with Web3 Foundation or examining the established history of that account on-chain.
Registrars can set a fee for their services and limit their attestation to certain fields. For example, a registrar could charge 1 DOT to verify one's legal name, email, and GPG key. When a user requests judgement, they will pay this fee to the registrar who provides the judgement on those claims. Users set a maximum fee they are willing to pay and only registrars below this amount would provide judgement.
Becoming a Registrar
See this page to learn how to become a Registrar.
There are multiple registrars on Polkadot. Unless no additional information is available here, you must reach out to specific registrars individually if you want to be judged by those.
Fee: 0 DOT
Fee: 10 DOT
Fee: 0 DOT
To find out how to contact the registrar after the application for judgement or to learn who they are, we can check their identity by adding them to our Address Book. Their identity will be automatically loaded.
Users can also link accounts by setting "sub accounts", each with its own identity, under a primary account. The system reserves a bond for each sub account. An example of how you might use this would be a validation company running multiple validators. A single entity, "My Staking Company", could register multiple sub accounts that represent the Stash accounts of each of their validators.
An account can have a maximum of 100 sub-accounts. Note that a deposit of is required for every sub-account.
Here is the how to set sub-identities article and a video tutorial on setting sub-identities using Polkadot-JS UI
Clearing and Killing an Identity
Clearing: Users can clear their identity information and have their deposit returned. Clearing an identity also clears all sub accounts and returns their deposits.
this support article for guidelines about clearing identities.
Killing: The Council can kill an identity that it deems erroneous. This results in a slash of the deposit.