Achieving Security in Proof-of-Proof Protocol with Non-Zero Synchronization Time

Among the most significant problems that almost any blockchain faces are of increasing its throughput (i.e., number transactions per unit time) and problem a long waiting time before block confirmation. Thus, for example, in common BTC blockchain, according to various estimates, is from 3 7 tps (transactions second), average confirmation (block considered confirmed if it has at least 6 blocks over it) 1 h. At same time, impossible solve these directly by size or generation intensity because this leads essentially decrease security first turn against double spend splitting attacks. Such lead inconvenience practical use cryptocurrencies pay goods services. Proposed few years ago, PoP consensus protocol potentially helps throughput, although was originally intended ensure stability “young” blockchains, with “small” PoW, through secure such as BTC. A provable called security-provided (SPB), one uses SPB achieve security-inherited blockchain. In paper, we give explicit formulas which describe how sufficient given level attack, depends on parameters both blockchains. It essential realistic model obtain results, taking into account synchronization times much closer real situation, but analytical difficulties obtaining results. The obtained convenient numerical calculations, numerous examples also work.