Petahash security is arguably excessive and a misallocation of capital. Unfortunately BTC creates a perverse incentive. This has been discussed ad nauseam. The alternatives so far are unappealing or unworkable. Alts may yet justify their existence as a class by finding a more adaptive mechanism or a superior security model.
I snipped the second paragraph cuz I couldn't understand it, but what do you think about parallel chains?
Is it possible to have a bitcoin clone running the same transaction code to run side-by-side with bitcoin but on another algorithm?
Sorry if not sense, Friday night
#Rant edit, had a moment of lucidity, but it faded
Like litecoin, but you don't make your own chain, you just take the existing chain and then listen for and include regular bitcoin transactions. When there is a discrepancy, like might happen with an attack, then at least you have some early warning, and some redundancy if it is necessary to "roll back" the Blockchain, if five or six other chains agree and only the sha256 chain differed, then maybe the consensus of miners would transfer to a consensus of chains?