/**
  * @return $this
  */
 public function useRandomSignatures()
 {
     if ($this->ecAdapter->getAdapterName() == EcAdapterInterface::SECP256K1) {
         throw new \RuntimeException('Secp256k1 extension does not yet support random signatures');
     }
     $this->deterministicSignatures = false;
     return $this;
 }