Verify Signature

This function will return true if a message passed as parameter has been signed by the passed address

const { cryptoWaitReady, decodeAddress, signatureVerify } = require('@polkadot/util-crypto');
const { u8aToHex } = require('@polkadot/util');

const isValidSignature = (signedMessage, signature, address) => {
  const publicKey = decodeAddress(address);
  const hexPublicKey = u8aToHex(publicKey);

  return signatureVerify(signedMessage, signature, hexPublicKey).isValid;
};

const main = async () => {
  //Some interfaces, such as using sr25519 however are only available via WASM
  await cryptoWaitReady();
  const isValid = isValidSignature(
    'This is a text message',
    '0x2aeaa98e26062cf65161c68c5cb7aa31ca050cb5bdd07abc80a475d2a2eebc7b7a9c9546fbdff971b29419ddd9982bf4148c81a49df550154e1674a6b58bac84',
    '5FHneW46xGXgs5mUiveU4sbTyGBzmstUspZC92UhjJM694ty'
  );
  console.log(isValid)
  // true
}

main();