From ecc
Prevents Ethereum hashing bugs in JavaScript/TypeScript by using true Keccak-256 instead of Node's NIST SHA3-256. For selectors, signatures, storage slots, and address derivation.
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Ethereum uses Keccak-256, not the NIST-standardized SHA3 variant exposed by Node's `crypto.createHash('sha3-256')`.
Provides Ethereum-correct Keccak-256 hashing in Node.js/TS to prevent bugs in function selectors, signatures, EIP-712, storage slots, and address derivation from Node's faulty sha3-256.
Provides QuickNode SDK and ethers.js patterns for production blockchain dApps: provider singletons, retry logic, batch RPC calls, multi-chain support.
Applies Solidity security best practices to prevent vulnerabilities like reentrancy, overflows, and access control issues when writing or auditing smart contracts.
Share bugs, ideas, or general feedback.
Ethereum uses Keccak-256, not the NIST-standardized SHA3 variant exposed by Node's crypto.createHash('sha3-256').
The two algorithms produce different outputs for the same input, and Node will not warn you.
import crypto from 'crypto';
import { keccak256, toUtf8Bytes } from 'ethers';
const data = 'hello';
const nistSha3 = crypto.createHash('sha3-256').update(data).digest('hex');
const keccak = keccak256(toUtf8Bytes(data)).slice(2);
console.log(nistSha3 === keccak); // false
import { keccak256, toUtf8Bytes, solidityPackedKeccak256, id } from 'ethers';
const hash = keccak256(new Uint8Array([0x01, 0x02]));
const hash2 = keccak256(toUtf8Bytes('hello'));
const topic = id('Transfer(address,address,uint256)');
const packed = solidityPackedKeccak256(
['address', 'uint256'],
['0x742d35Cc6634C0532925a3b8D4C9B569890FaC1c', 100n],
);
import { keccak256, toBytes } from 'viem';
const hash = keccak256(toBytes('hello'));
const hash = web3.utils.keccak256('hello');
const packed = web3.utils.soliditySha3(
{ type: 'address', value: '0x742d35Cc6634C0532925a3b8D4C9B569890FaC1c' },
{ type: 'uint256', value: '100' },
);
import { id, keccak256, AbiCoder } from 'ethers';
const selector = id('transfer(address,uint256)').slice(0, 10);
const typeHash = keccak256(toUtf8Bytes('Transfer(address from,address to,uint256 value)'));
function getMappingSlot(key: string, mappingSlot: number): string {
return keccak256(
AbiCoder.defaultAbiCoder().encode(['address', 'uint256'], [key, mappingSlot]),
);
}
import { keccak256 } from 'ethers';
function pubkeyToAddress(pubkeyBytes: Uint8Array): string {
const hash = keccak256(pubkeyBytes.slice(1));
return '0x' + hash.slice(-40);
}
grep -rn "createHash.*sha3" --include="*.ts" --include="*.js" --exclude-dir=node_modules .
grep -rn "keccak256" --include="*.ts" --include="*.js" . | grep -v node_modules
For Ethereum contexts, never use crypto.createHash('sha3-256'). Use Keccak-aware helpers from ethers, viem, web3, or another explicit Keccak implementation.