In the recent days – when Ethereum’s Ether-blockchain forked into ETH and ETC – we could not do else but read the term “Replay Attack”. If you wondered what exactly a replay attack is, continue to read. I will explain.
The basis of the Replay Attack is the fact that all wallets which contained Ether at the time of the fork will credit their corresponsing Ethereum Classic wallets with ETC. So, if you had, say, 100 ETH in your wallet, then you’ll be credited with 100 ETC.
But that’s not an automatic process (well, it is, but only under certain circumstances): it only works on exchanges which support the quasi-new Ethereum Classic chain.
Poloniex is an exchange which supports Ethereum Classic. If your wallet contained Ether before the hard fork, you’ll be credited the same amount of ETC. This also works post-fork, and that’s where the replay attack comes into play. The only thing you need to do is find an exchange which still uses old wallets, which were created before the hard fork happened.
If you were to exploit the Replay Attack (which I don’t condone, recommend or do), you’d have to do the following:
- find a service or an exchange which still uses pre-fork wallets (like Coinbase, at the time of writing this post)
- buy ETH there using BTC, and send it to an exchange which supports ETC
- when the ETH arrive in your wallet, you’ll find the same amount of ETC being credited to the respective wallet
- sell your ETH and ETC for BTC and send back the BTC to the service or exchange using pre-fork wallets
- rinse and repeat
Just to make this clear: I don’t suggest doing this, and neither am I doing this.
I’m posting about this because I think Coinbase should also be supporting ETC, so their users who own(ed) ETH can also get their share of ETC. It’s only fair and they should treat their users that way.