??? ?? ??? ????? ???? ? ???? ???? ?? ??????? ?? ??? ???????? ??????? ???????? ? ??? ?? ???? ???? ?????? ????? ??????? ?????? ??? ????? ??????? ??? ???? ? ???????? ????? ??????? ??????? ???????? ?? ???? "??????? ????????". ??? ?? ???? ???? ?? ??????? ???????? ????? ??????? ??? ???? ?? ??

This also helps prevent any individual from changing parts of the block chain to roll back their own spends, which may be accustomed to defraud other people. Mining makes it exponentially harder to reverse a earlier transaction by requiring the rewriting of all blocks adhering to this transaction.