?????? ?? ??? ???????? ???? ?????????? ?? ????????????? ??? ????? ?? ????? ???? "? ??????? ?? ???????? ??? ??????????? ?????????".Cryptocurrencies use many timestamping strategies to "establish" the validity of transactions added into the blockchain ledger with no want for just a trusted third party.??? ??? ?? ??? ????? ???? ??? ????? ?????? ?? ???