}
}
public void changeWalletPassword(char[] oldUtf16Password, char[] newUtf16Password) throws WrongPasswordException {
// check if aes key for new password can be generated before decrypting
KeyCrypterScrypt keyCrypter = new KeyCrypterScrypt();
KeyParameter aesKey = deriveKeyAndWipePassword(newUtf16Password, keyCrypter);
updateLastWalletChange(wallet);
if (isWalletEncrypted()) {