BTC.com has added replay protection and a coin extraction tool for the Bitcoin Cash/SV hardfork. This makes it safe to spend Bitcoin Cash from their wallet, without the possibility of losing your newly minted Bitcoin SV in the process. It also allows users to split their coins, obtaining both their Bitcoin Cash and Bitcoin SV.
Replay protection is a way to head off a replay attack, which becomes an issue after any contentious hardfork. A replay attack works because the user information from before the fork on the two split blockchains is identical. When a user sends a transaction, they sign that transaction to prove they hold the private keys to that wallet. During a replay attack, the attacker will copy that information. Since the private key is the same on both chains, the signature will be accepted as valid on the other chain as well, even though the attacker doesn’t hold the private keys.
Replay protection can be done in two ways. It can be done on the coin developer level by making transaction from one chain invalid on another by changing the way transactions are handled. This could be done by changing the address format or changing some other parameter so that the two chain’s transactions will be incompatible.
But that would require a major change to the coin’s wallets, and all of them would need to be upgraded.
Another way to prevent replay attacks is to have users move their coins in a safe environment after the fork. BTC.com is providing a way to do that. Essentially, users send their bitcoin cash back to themselves, while BTC.com injects a coin made from after the fork. That ensures that any future transactions won’t be valid on the Bitcoin SV blockchain. They will be coming from an address not yet created on the Bitcoin SV chain. After completing the process, users can then “extract” their Bitcoin SV from BTC.com and move it to a Bitcoin SV compatible wallet. BTC.com does not currently have a Bitcoin SV compatible wallet, so finding a place to put your SV coins will be up to you.
If you are not a member of BTC.com or if you have another wallet you would like split, BTC.com can do that as well. Simply sign up if you are not already a member and then select the “Import Wallet” option and then change the type from Bitcoin to Bitcoin Cash. After importing, you will have Bitcoin Cash in BTC.com which you can then split as described above. Once you have your Bitcoin Cash and Bitcoin SV split, you can move both back to your wallet of choice.
Hardforks are a complicated process that causes headaches for everyone involved. Even those who wouldn’t care to participate were all but forced. With Bitcoin Cash’s price drop, Bitcoin SV redemption is a useful resource to regain some of that lost value.
But at least sites like BTC.com are making it easy for users. Hopefully coin-wide protections will be put into place at a future date. That would at least allow Bitcoin Cash users to operate normally without fear of losing their Bitcoin SV. In case they decide to redeem them at a later date the coins would remain in their original account. Assuming the user keeps track of their private keys, the coins should still be accessible.
You can read BTC.com’s instructions on how to split your coins here.
We will continue to cover the ongoing fallout from the Bitcoin Cash / SV hardfork.