throws InvalidKeyException
{
if (key instanceof BCRainbowPrivateKey)
{
BCRainbowPrivateKey k = (BCRainbowPrivateKey)key;
return new RainbowPrivateKeyParameters(k.getInvA1(), k.getB1(),
k.getInvA2(), k.getB2(), k.getVi(), k.getLayers());
}
throw new InvalidKeyException("can't identify Rainbow private key.");
}