Ethereum

driver

ethereum

curve

secp256k1

address formats

EIP-55 hex

SLIP-44 coin

60'

Load it

import { useBlockchain, blockchains } from "@agntn/keys";

const ethereumChain = useBlockchain(await blockchains.ethereum()());

The address

Uncompressed public key without the 04, Keccak-256, last 20 bytes, 0x, then the EIP-55 case checksum.

const privateKey = "0000000000000000000000000000000000000000000000000000000000000001";
const publicKey = ethereumChain.getKeyPublic(privateKey);

ethereumChain.getAddress(publicKey); // 0x7E5F4552091A69125d5DfCb7b8C2659029395Bdf

Yes, that is the address of private key 1. It shows up in a lot of test suites.

Validation

ethereumChain.validateAddress("0x7E5F4552091A69125d5DfCb7b8C2659029395Bdf"); // true
ethereumChain.validateAddress("0x7e5f4552091a69125d5dfcb7b8c2659029395bdf"); // true, no checksum to check
ethereumChain.validateAddress("0x7e5F4552091A69125d5DfCb7b8C2659029395Bdf"); // false, bad checksum

Lowercase and uppercase pass, mixed case has to match. A rejected mixed case address is almost always a copy and paste that lost a character somewhere, so treat false as "look at it again", not as "this address does not exist".

Signing

signMessage prepends "\x19Ethereum Signed Message:\n" + length, hashes with Keccak-256, and signs with secp256k1. That is personal_sign, so the signature verifies in MetaMask, ethers, viem, and anything else that follows EIP-191.

const signature = ethereumChain.signMessage("hello", privateKey);
ethereumChain.verifyMessage("hello", signature, publicKey); // true

One driver, every EVM chain

Ethereum is AbstractEVMBlockchain with a name and coin type 60. Base is the same class with a different name. The EVM guide explains why one private key gives one address on every EVM chain and how to add another one in two lines.