QChain has a developed system of smart contracts, describing (formalizing) any event in human activity, from the purchase and sale of goods and services, accounting of logistical events, ending with the tracking of copyrights and interaction with legal entities, and including a number of self-executable transactions (smart contracts) in any area of human activity. QChain is a complete blockchain platform capable of both private and public access for public, commercial and private activities. It is a platform that can be used with both thin clients and more powerful processors, base stations, and, with the latest electronic and computer technology, including quantum computers. The capabilities of smart contracts allow you to create a 4-dimensional blockchain rather than a one-dimensional blockchain. In practice, this allows to conclude a transaction between several participants at once (up to 10 transactions), which greatly expands the scope of this network.