A cryptocurrency is a type of digital currency that has a decentralized payment system (there is no internal or external administrator or any equivalent) that works in a fully automatic mode. The cryptocurrency itself does not have any special material or electronic form-it is just a number indicating the amount of data of payment units, which is recorded in the corresponding position of the information package of the data transfer Protocol and is often not even encrypted, as well as all other information about transactions between the addresses of the system. At the same time, cryptographic methods are used to generate the address and verify the authority to operate with it (a digital signature based on a public key system, the order is available only to the owner of the secret key corresponding to this address), as well as to form a transaction package and its relationship with other packages (sequential hashing, which makes it impossible to change information about the amount of cryptocurrency). The system has no information about the owners address or the fact of creation of the address (the address can be generated completely offline even without connecting to the network and without saying anything to the network later) — that is, there is no mechanism to verify that the recipient address actually exists or that the key access is not lost. The lack of information about the owner is the basis for (but not limited to) the anonymity of transaction participants. According to their economic conditions and consequences, cryptocurrency payments are more similar to cash payments than to non-cash payment options, although cryptocurrencies are developed primarily for remote purchases (for example, via the Internet).