Re: [neㄘcash, ᨇcash, net⚷eys, or viᖚes?] Name AnonyMint's vapor coin?
Against Dash and Satoshi's design (e.g. Bitcoin) that can theoretically be executed with a much less costly Finney attack (where the attacker wins a block but doesn't announce it right away and first announces his double-spend, which is even more likely in Dash's InstantX because the confirmation is instant making it much more feasible to fool the unwary merchant who was assured that InstantX is instantly confirmed so not to wait for chain confirmations), so no need to invest such massive resources. And there are other less costly attacks specifically on Dash that monsterer alluded to and I will be following up on in future posts.
But if the InstantX lock has been acquired (and the merchant will see in his wallet that the lock is on within a couple of seconds) the attacker's delayed block will be rejected by the network because it contains a conflicting transaction (all the honest nodes will obey the lock). To me it rather looks like InstantX is safer than Bitcoin in that respect or am I again missing something.
And if the attacker releases the block within the propagation delay so that some see the block announcement before they see the lock announcement. So there is an ambiguity. Which is correct the instantX announcement or block chain announcement?
I don't know the exact details but this seems non-issue to me. If the merchant receives the false block before he gets to know about the IX lock...
Don't think only of the merchant (payee). Think of the consistency of the block chain. Pay attention to the issue of forking (disagreement between mining nodes which leads to them refusing to mine each others' chains), which afaics is the main threat (other than when masternodes can lie and get away with it, which is another attack vector monsterer caused me to realize I need to explain because I did also consider that attack vector in my design).