Is it possible to claim Bitcoin Cash from an exchange that does not support it

Question

Is it possible to claim BCH without knowing private key?

I have some Bitcoins in CoinsBank account (https://coinsbank.com) topped up before the fork. CoinsBank officially declared that they will never support BCH, so I'm seeking for ways to claim it.

For example, what if I create a BTC wallet, send my bitcoins there, and then broadcast the same transaction in BCH network?

Answer 1

You can't claim BCH without knowing private key, even if you withdraw that Bitcoin to your BTC wallet. Because, it means that you will get Bitcoin into your wallet after BCH fork.

To claim BCH, you have to have Bitcoin on your wallet before BCH fork.

If you make a BTC transaction, it is not possible to broadcast the same transaction in BCH network manually. BCH uses "sighash_forkid" to distinguish, so BCH won't accept the transaction that you made and broadcasted to BTC network.