| Hi, As you may be aware ETC recently had a series of reorgs and we wanted to provide some advice on mitigating the impact of such attacks. Please note that this email primarily applies to anyone who received ETC in the past few days, plans to in the future, runs an exchange, or operates a mining pool. If this does not apply to you then you can safely ignore this message. Firstly, please note that this is not a situation unique to ETC and is how all PoW networks work, and the general strategy below helps to provide protection against double spends on all PoW networks. We are suggesting that you increase confirmations for any transactions to a minimum between 2,500 to 5,000 blocks. As you may know, each block on a PoW-based chain requires a certain amount of work or cost to mine, in the case of the reorgs on ETC it is relatively cheap to do the ~100 block double spends that we have seen. If we compare ETC's network to Bitcoin we find that roughly every 2,500 blocks is equivalent to 1 Bitcoin block in rough terms of cost to mine. We therefore suggest 2,500 to 5,000 blocks to achieve the same guarantees as 1 to 2 Bitcoin blocks. If you are doing particularly large transactions we suggest you wait a number of blocks roughly equivalent to the value you're transferring. For example, 1 block on the ETC network costs slightly less than ~4 ETC to mine, so if you were to perform a transaction of 40,000 ETC it would be recommended that you wait at least 10,000 blocks before considering the transaction as confirmed. Thank you for taking the time to read this email, please note that this is only mitigation advice and you should perform your own research and follow all of your own best practices. Please feel free to reach out if you're an exchange or mining pool that needs further info. ETC Cooperative | 636 Avenue of the Americas, New York |
Wednesday, January 9, 2019
Mitigation Approach Regarding ETC Reorgs/51% Attacks
