COMPUTER SIMULATION OF DECENTRALIZED NETWORK

This paperis dedicated to the development of a software system for computer modeling (simulation) of a decentralized network with the ability to perform calculations on distributed nodes.The results of the creation of a such simulation system for decentralized computer networks arc discussed. This system is used during research and implementation of different cryptographic algorithms based on modular arithmetic.

 In decentralized networks, there arc no dedicated servers, and each node (peer ) acts like a client and a server. Unlike the client-server architecture, such an organization allows to keep the working capacity of network at any number and any combination of available nodes. Considering the steady growth in the number of applications, users and devices in these networks, issues of ensuring information security in such networks arc particularly relevant.

Cryptographic means of information protection can be used to solve the problems of confidentiality and authentication during the interaction in the network. Encryption of the data flow between decentralized network nodes allows not only to protect the data itself, but also to hide the fact that network connection has taken place.

The main tasks of cryptographic protection of information in decentralized networks arc the following: data encryption to ensure confidentiality during storage and transmission over the network between nodes; the usage of hash functions to control the integrity of data; usage of message authentication codes and electronic digital signatures for message authentication. An important task for this type of networks is to provide cryptographic protection of information during data transmission through communication channels and during storage.

During the research and development of cryptographic systems based on modular arithmetic in the Laboratory of Information Security of the Institute of Information and Computational Technologies, it was important to investigate possibility and efficiency of usage of the developed symmetric and asymmetric cryptographic algorithms in network data transmission. For this reason, the work on the development and implementation of a simulation system of decentralized networks is carried out.

The analysis of existing programs for simulating peer-to-peer networks is performed. The typical requirements for these systems such as workflow architecture, usability, scalability, statistics, portabilitywcrc evaluated. It was shown, that the most of the simulation systems, which arc available from the open sources, arc obsolete and do not allow to run network simulation on distributed nodes. According to it, a new simulation system has been developed.

The developed system includes the following components: topologvdesign and monitoring system; node process manager; computing process instance. First the component of topology design creates a network topology based on the specified parameters. Based the created topology process managers create instances of processes that simulate the operation of individual nodes. Building a node manager in a separate component allows to distribute the process of creating and managing nodes to different computers. Each process performs calculations and acts like a separate network node. A process is

assigned a unique identifier and a lambda function that will be executed by the process and simulate the calculation process. Processes can exchange data through this protocol by using an arbitrary form of messages, the content of which depends on specifications in the processes of the lambda functions. The system uses an event-based workflow, that is, a state change causes corresponding events in related objects. The network monitoring component receives every status message from nodes in the network.

The system is implemented in the JavaScript language using the Node.js and AngularJS web platforms. Processes are interconnected by passing a message through the HTTP protocol by using WebSocket technology.

The structural and protocol design of the system is discussed. The proposed structure of the system allows users to apply their own encryption algorithms and security protocols to the simulation process. The developed system of decentralized network simulation has a feature of working on distributed nodes, for example on different computers, either physical or virtual. This feature makes the developed simulation system a useful tool during research and implementation of different cryptographic algorithms based on modular arithmetic. This gives an opportunity to evaluate efficiency of different cryptographic schemes in a network flow.