static Bytes random(final int size) {
    final byte[] iv = new byte[size];
    RANDOM.nextBytes(iv);
    return Bytes.wrap(iv);
  }
Computes the secrets from the two exchanged messages.
ethereum/p2p/src/main/java/org/hyperledger/besu/ethereum/p2p/rlpx/handshake/ecies/ECIESHandshaker.java