Before asking this question you should learn what is the consensus problem and learn what is blockchain from cryptosystems' perspective (hint: they are two comp

Before asking this question you should learn what is the consensus problem and learn what is blockchain from cryptosystems' perspective (hint: they are two completely different things). It's pointless to discuss research if the interlocutor doesn't understand the basic terminology of the field. You could start with the Byzantine generals problem, its proof about lower bounds, and the relation between the lower bounds of Byzantine generals and blockchain.