The dearth of a central authority also can make cryptocurrencies safer. "It can be hack-proof since there isn't any 1 central point of failure," points out David Donovan, executive vp at Publicis Sapient.? ?????????????? ???? ?????????? ????????? ??? ??? ?????????????? ??? ?????????? ?????????? ???? ????? ?? ??? ???????? ???? ???.????, ???????? ???