Unification type data structure guaranteeing monotonicity and cryptocurrency system using the same

A cryptocurrency system making use of unification type data structure guaranteeing monotonicity, including:

• a first server including a first controller, a first communication unit, and a first non-transitory storage medium;
• a second server including a second controller, a second communication unit, and a second non-transitory storage medium;
• and
• a clock unit independent of the first and second servers,
• wherein
• the second controller includes a unification unit carrying out unification process,
• the first controller generates cryptocurrency comprised of tree-structured data having an attribute, and transmits the cryptocurrency to the second server,
• the second controller, when the second server receives the cryptocurrency from the first server, makes in the second non-transitory storage medium a temporary tree-structure of cryptocurrency candidate to be received from the first sever,
• the unification unit carries out the unification process to compare the attribute of the cryptocurrency having been generated by the first controller to the attribute of the candidate cryptocurrency,
• the unification unit generates a new tree-structure only when both of the attributes logically match each other, and does not generate a new tree-structure when both of the attributes do not logically match each other,
• the cryptocurrency is designed to have such a structure that at least amount among value and amount thereof is reduced with passage of a predetermined period of time,
• the clock unit transmits hashed time data to the second server every predetermined period of time,
• the second controller writes the hashed time data into the cryptocurrency, and prohibits the hashed time data to be overwritten, and
• the second controller transmits a reduced amount of the cryptocurrency to the first sever at the passage of the predetermined period of time having written into the cryptocurrency.