In-depth essays · #34 / 50 · Wallets, Oracles, Security & Payments

From 0x71C… to vitalik.eth: How the Ethereum Name Service (ENS) Works as the City’s Address Book

Turning 42-character hexadecimal strings into human-readable, censorship-resistant on-chain profiles

In the early days of the internet, visiting a server meant typing numerical IP addresses like 142.250.190.46 until DNS mapped them to names. On Ethereum, ENS (Ethereum Name Service) does the same for 42-character hexadecimal addresses—turning 0xd8dA…6045 into vitalik.eth.

1. Why Hexadecimal Addresses Invite Copy-Paste Mistakes and Address Poisoning

Because nobody can memorize a 40-digit hex string, users often check only the first and last four characters when pasting an address—a habit exploited by ‘address poisoning’ scammers who generate vanity addresses with matching prefixes and suffixes. Human-readable .eth names eliminate that ambiguity.

2. Smart Contract Registries: Names Owned as NFTs, Not Rented from a Corporate Broker

Every .eth name is registered directly in immutable smart contracts on Ethereum L1 and represented as an NFT in your wallet. A single ENS record can resolve not only your Ethereum address, but also Bitcoin addresses, avatar images, text records, and IPFS websites.

3. Scaling Names to L2 Districts via CCIP-Read: Basenames and Linea Names

Using ERC-3668 (CCIP-Read), ENS now resolves subnames stored on L2s with cryptographic proofs—powering low-cost district identities like *.base.eth on Base and *.linea.eth on Linea.

4. Looking Up Any .eth Name Directly in Ethereum City

Type any .eth name into Ethereum City’s Wallet Lookup bar and the city resolves it live against the mainnet ENS registry to highlight that wallet’s activity across all 39 districts.

Related districts in the city

Related glossary terms

This essay is an explainer written to help you read the city; it is not investment advice. Facts on this page are as of 2026-10 and may change. If you spot a mistake, please tell us through the contact page.