The relationship between precision, safety, and completeness. Accuracy determines security: the more precise a system is, the safer it is. The completeness determines the accuracy: the more complete a system is, the more precise it is. Why is Bitcoin designed to be so secure? Because he incorporates the irreversibility of time into his ultra poor iterative techniques, achieving 100% accuracy and 100% safety by approaching perfection infinitely. The first element of designing cryptocurrency is the security of the system. So we should consider the completeness of the system in order to obtain accuracy to ensure its security.