Bitcoin Forum

I want to dump some of my Bcash coins stored in my paper wallet using trezor sweep function. I don't want to move the bitcoins stored on the same address. What risks am I taking? Only replay attacks?

That should really be the only risk. Although BCC says it is relay proof, there may still be problems with the way it functions as it's not as stable/secure as BTC.

I think there's something about exposing the private keys you're using but theoretically, there shouldn't be too much of a problem there as it's a hardware wallet so you're just exposing the private keys to a trezor wallet.

bottom line? don't risk it. scammers everywhere. if you move bch then please move your btc to a new wallet too. can't be too careful and it's not worth the risk

It should be easy to do without risks. Import your BTC to Electrum wallet and from there, import the private keys to Electron Cash a fork of Electrum wallet and then send to an exchange and dump all you want. After you have done this send your bitcoins back to your hardware wallet. I do not see any risk if done such way but I am not that experienced with BCC so proceed with caution. Here is a link to start to import your Trezor private keys to Electrum.

https://doc.satoshilabs.com/trezor-apps/electrum.html (https://doc.satoshilabs.com/trezor-apps/electrum.html)

Moving BCH first was replay protected from the start. Moving BTC first was initially only opt-in replay protected, but the Bitcoin ABC team made some last minute changes before the fork that should replay protect BTC transactions by default as well (assuming the majority of BCH nodes and miners have updated their client software accordingly).

So in theory you should be safe from replay attacks.

Apart from that, remember that by sweeping the paper wallet you're exposing it's private key to your system, so the regular caveats about online hot wallets apply. Emptying your old paper wallet and sending your BTC to a new cold storage address (eg. your Trezor, since you mentioned it) would be prudent.

Thank you for your answers!

What about this example?
I had BTC and BCH on coinomi wallet. Dumped BCH and exchanged them to another coin. Then deactivated the BCH wallet in coinomi.
Is there also a possibility to loose the bitcoins? For example when I export private key.

Not Dangerous unless you share your private key to others.