A major issue Dossa pointed out was block reorgs, which are technically possible in PoW systems. In a block reorg, individual blocks containing transactions are rolled back to rescind a disputed transaction. However, ethereum has only experienced one reorg ever following the infamous
DAO hack of 2016.
For businesses working with regulated assets and security tokens, even strong statistical guarantees aren’t enough, Dossa said.
“When a [Substrate] transaction is finalized, it cannot be undone,” he added.