.It is dangerous to follow all precautionary measures of the blocking system - a kind of bank safe in which tokens and a register with records of transactions are stored. Block-book is a series of records (blocks) containing data and links with which each block is attached to the previous one. In the case of a block, a kind of bank safe that stores tokens and a register with transaction records. Block is a series of records (blocks) containing data and links, with which each block is attached to the previous one.