Blockchain Networks – Security Aspects and Consensus Models

A. Wilczyński, A. Widłak
Journal of Telecommunications and Information Technology, Volume 2, 2019, Pages 46-52

Data integration and fast efective data processing are the primary challenges in today’s high-performance computing systems used for Big Data processing and analysis in practical scenarios. Blockchain (BC) is a hot, modern technology that ensures high security of data processes stored in highly distributed networks and ICT infrastructures. BC enables secure data transfers in distributed systems without the need for all operations and processes in the network to be initiated and monitored by any central authority (system manager). This paper presents the background of a generic architectural model of a BC system and explains the concept behind the consensus models used in BC transactions. Security is the main aspect of all defined operations and BC nodes. The paper presents also specific BC use cases to illustrate the performance of the system in practical scenarios.


Over the few past years, the Blockchain (BC) became the topic of interest for many engineers and companies, especially from financial and ICT sectors. This makes BC one of the most popular technologies used in ICT infrastructures developed for the needs of public institutions, financial markets, cloud storage systems and many other domains. BC may be de ned as a decentralized computer network without a central management unit. Data stored in BC blocks within such a system may be eciently protected against external attacks. Data in a given block cannot be modi ed without an additional, signi cant power supply for the ICT infrastructure, which is usually not provided (it would rapidly increase the cost of energy used in BC nodes). In BC networks, the extra supervised transactions are not necessary (no central authority), each node is autonomous and may take decisions about transactions based on consensus procedures. This prevents any data manipulation
and intrusions aimed at impersonating entities and performing unauthorized operations. Such consensus models de fine crucial procedures of the process of creating the chain of BC blocks and data transactions…


Blockchain technology is the direction in which the industry will be heading over the coming years. The use of cryptographic algorithms ensures appropriate level of security that is required by most ITC environments. Full transparency and data integrity make it suitable for use in many data
processing-related domains. Decentralization and the lack of a central supervisor makes the processes where a verifi cation unit is needed faster and more efficient, due to the lack of the human factor and full automation. The trust built by nodes within the network ensures that all operations are carried out in accordance with the rules de fined for a given network. Many systems based on Blockchain technology are already in existence. They are subject to continuous improvement and their number may be expected
to grow.