ECPrivateKeySpec priKeySpec = new ECPrivateKeySpec(
new BigInteger("145642755521911534651321230007534120304391871461646461466464667494947990"), // d
params);
ECPublicKeySpec pubKeySpec = new ECPublicKeySpec(
curve.decodePoint(Hex.decode("045894609CCECF9A92533F630DE713A958E96C97CCB8F5ABB5A688A238DEED6DC2D9D0C94EBFB7D526BA6A61764175B99CB6011E2047F9F067293F57F5")), // Q
params);
Signature sgr = Signature.getInstance("ECDSA", "BC");
KeyFactory f = KeyFactory.getInstance("ECDSA", "BC");