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Nick Johnson

nick@ens.domains

Ethereum Name Service

This event is brought to you by workonblockchain.com

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Overview

What ENS is & how it works
ENS resolvers in practice
Using ENS in DApps
Registrars & name registration
State of ENS

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What is ENS?

0x112234455c3a32fd112

30c42e7bccd4a84e02010

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What is ENS?

inigomontoya.eth

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More than just names

ENS names contracts and accounts, but also…

Swarm & IPFS records
Legacy DNS records - IP addresses, mail exchangers
Identity attestation
Stores contract interfaces

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What is ENS?

eth

inigomontoya

wallet

metamask

alice
bob

oraclize

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ENS Architecture

ENS consists of two main components: the ENS registry and ENS resolvers. The registry is a single contract that maintains a list of all names in the system, and stores two critical pieces of information about each: the address that owns the name, and optionally, the address of the resolver for that name. An owner has the right to update the resolver record, to transfer the domain to another account, and also to create subdomains. The registry’s primary job is to serve as a directory of resolvers.

Resolvers are the contracts that actually turn names into addresses and other identifiers. Anyone can write and deploy their own resolver that suits their needs.

This separation of an extremely straightforward central directory, and distributed and upgradeable resolvers gives ENS its extensibility and flexibility.

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Resolving a name

Resolving a name in ENS is a two-step process. First, you query the registry for the address of the resolver for the name you’re interested in (in this case, ‘foo.eth’). If there’s a resolver for that name, the registry responds with its address. Then, you call that resolver, asking it for the record you’re interested in - in this case the Ethereum address associated with the name, but you could also be querying for a swarm hash, metadata, or just about anything else.

The registry’s only job is maintaining lists of resolvers and owners for domains. Because of this, it has no knowledge of the different record types you can resolve, or different ways that resolution might be accomplished - which is a good thing, because it allows us to add new functionality just by writing new resolvers, with no need to modify or upgrade the registry at all.

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ENS by example: Resolvers

Contract MyResolver {

address me;

function MyResolver() {

me = msg.sender;

}

function addr(bytes32 node) constant returns (address) {

return me;

}

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Using ENS from Javascript

var ENS = require(‘ethereum-ens’);

var ens = new ENS(web3);

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Looking up names

var address = ens.resolver(‘inigomontoya.eth’).addr();

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Reverse resolution

var name = ens.reverse(‘0x112234455...’).name();

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Setting up reverse resolution

In JS:

reverseRegistrar.claim(eth.accounts[0],

{from: eth.accounts[0]});

In Solidity:

reverse.claim(msg.sender);

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Contracts in web3

var testContract = web3.eth.contract(

[{"constant":true,"inputs":...}])

var test = testContract.at(“0x0904dac3347ea47d208f...”);

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Contracts in ENS

var test = ens.resolver(‘inigomontoya.eth’).instance();

A new ENS standard lets us store contract ABIs in ENS, enabling you to get everything you need to interact with the contract with nothing more than its name. After deploying your contract, you tell your resolver its address, and the contents of your ABI. Afterwards, anyone can fetch both given your contract’s name.��To streamline things even further, the ENS library offers a method that fetches both ABI and address and constructs a new contract instance from them, so you can get a usable contract in a single line of code, starting with nothing more than its ENS name.

It’s also possible to associate an ABI with a contract’s reverse record, and the ENS library will automatically look there if it doesn’t first find it associated with the name. This way, you can provide your users with an interface for your contract that can be found no matter what name it’s referenced by - or even if it doesn’t have an ENS name at all.

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Registrars in ENS

REGISTERED

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ENS by example: Registrars

contract SimpleRegistrar {

ENS ens;

bytes32 root;

function claim(bytes32 label) {

if(ens.owner(sha3(root, label)) != 0)

throw;

ens.setSubnodeOwner(root, label, msg.sender);

}

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The .eth registrar

For the .eth top-level domain, we’ve designed a registrar based on an auction process known as a ‘Vickerey Auction’. An auction is opened when the first person wants to bid on a name, and runs for a fixed period. During that interval, anyone can place a secret bid on the name. At the end of the auction, all the bids are revealed simultaneously, and the highest bidder wins - but only pays the amount of the second-highest bid. If nobody else bids on the name you want, you win it for just 10 finney - one one hundredth of an ether.

The money from the bid is put into a deed account. Users can recover their money from the deed account by surrendering the name, allowing others to register it in their place - so the cost of a domain is the opportunity cost of locking your funds up.

In the longer term, we expect that this entirely automated registrar will be replaced with a more sophisticated system, with community submissions via the EIP process, starting a year after launch on mainnet. When the transition does happen, anyone with a name will have the option of transferring it to the new registrar, or surrendering the name and recovering their deposit.

If you want to learn more about the timeline and details for this, check out the video of my ENS talk from DevCon Two.

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ENS status

Launched on mainnet on May 4 2017
‘Soft launch’ finished July 12 2017
Responsible for 24% of all gas usage on mainnet

ENS is available right now on Ropsten. Users can register .eth domains and .test domains - .test domains use a simple first-in-first-served system, and expire 28 days after registration; they’ll only be available on Ropsten for test purposes.

ENS will soon be ready for deployment on mainnet using the auction system I just described. The first set of auctions will end 4 weeks after deployment - this is to give people lots of time to become aware of the system and to make sure the initial set of auctions are fair - then reducing to a 1 week duration for ongoing operation.

At or shortly after launch, we hope to have integration ready in a number of popular DApps, with more to come after launch. We’re pleased to announce that My Ether Wallet, Mist, and Metamask all intend to have at least preliminary ENS support ready for launch, with more features to come.

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180,822 names auctioned

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Ξ168,595 Ether deposited

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Top Domains

ethfinex.eth Ξ201,709
sportsbet.eth Ξ188,888
consensys.eth Ξ184,811
weifund.eth Ξ184,400

darkmarket.eth Ξ20,103
openmarket.eth Ξ10,054
exchange.eth Ξ6,660
blackjack.eth Ξ5,910
tickets.eth Ξ2,976

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Client Adoption

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What’s next

Voluntary dispute resolution / blacklisting
Exchange integration
DNS on ENS
ENS on DNS
Designing the permanent registrar

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Any questions?

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