Blockchain technologies allow you to make records about files and create a single registry that is not owned by one particular owner. This is a database that is distributed among different owners, and the records in it are connected in such a way that it is impossible to change any record in the middle of the chain. If you recorded in Blockchain, then it stayed there forever. This is very useful, for example, in order to make a single register of property owners. Or, using the example of our Acronis True Image product, this property allows you to check whether the file you are restoring from the backup copy is unchanged. That is, you can make sure that you have exactly the file that was placed in the backup, say, five years ago. In order to make sure that this is the case, various mathematical algorithms are used.