Introduction
There is no point in proving today the advantages of blockchain architecture over traditional databases. The fact is that the growing number of companies switching to blockchain solutions is already sufficient confirmation of this statement. Many companies not only use blockchain tools in their activities, but at the same time develop internal blockchain networks for corporate clients. In this regard, more than ever, the demand for experienced, professional and responsible partners in training, consulting and support of any blockchain-based project for any large, medium or small company is increasing. The interaction algorithm in the chain “customer company – blockchain experts” is simple and reliable. The company offers its idea or vision of any planned blockchain project, and the experts at https://dysnix.com/blockchain-consulting-service plan a process flow chart with a goal to bring this idea to life, and to support its practical implementation.
Several years ago, an interesting study was conducted in European countries about the level of trust of citizens of these countries in various organizations and structures that influence people's lives. As a result, it turned out that more than half of all respondents said that they have the greatest trust in non-profit organizations and businesses. Accordingly, people have much less trust in governments and the media. It is significant that two years later, similar studies showed more essential decrease in trust in governments and the media. The conclusion suggests itself: trust in classical centralized structures is constantly falling. An increase in mistrust means, neither more nor less, an increase in costs in a variety of business processes. In many ways, this fact has become one of the main reasons for the growing popularity of decentralization in many areas of human activity, and therefore the intensive transition of many companies to blockchain solutions. The benefits that companies receive by switching to blockchain include guarantees of the immutability of the history of all actions within the blockchain and the possibility of real-time auditing. As a result, the profit of companies is to significantly simplify the resolution of disputes and, as a result, to generally increase confidence in the system as such.
Structure of data storage in a block
Ensuring the immutability of each block in the blockchain occurs due to its structure, which is quite tenable, and mainly includes a record of the current operation (transaction) with a link to the previous block. This information is a unique cryptographic hash function or, in other words, a digital fingerprint of a file of a fixed length. There is one requirement for this cryptographic function – it must be one-way. This means that the hash should not make it possible to find any object with its predefined value, and, moreover, make it impossible to find two arbitrary objects with the same hash value. In addition to the hash function, each block contains metadata about all previous transactions. The entry of transactions into a block is ensured by a binary structure called the “Merkle Tree”. The essence of this structure is as follows: all transactions are placed on the first lower level of the Tree. The next second level contains hashes from each transaction, the third level consists of hashes of pairs of elements of the previous level. Next, each next, higher level is formed from pairs of hashes of the previous level, and, as a result, a single final hash is located at the top of the Tree. It should be clarified that all levels of the Merkle Tree are called “leaves”, and the final level at the top of the Tree is called the “root”.
Consensus and categories of its algorithms
The functioning of a blockchain cannot be ensured without one or another algorithm for achieving consensus. In simple terms, the operation of the blockchain must be ensured by an agreement within a group of equal network participants on a certain digital fingerprint of the next block (hash). The following requirements for the consensus algorithm are established:
– Termination: the decision of each participant must be made within a certain, finite time.
– Agreement: all values of the decisions of each “correct” participant must match.
– Integrity: there must be a guarantee that each participant receives an agreed value, as a single value proposed by all the “correct” participants.
It should be noted that the consensus problem can be solved differently in different blockchains. In practice, there are many consensus algorithms depending on a particular blockchain network, but they can be grouped into two categories – “economic” algorithms and “mathematical” algorithms.
The most famous today PoW (Proof-of-Work) consensus algorithm belongs to the economic direction. The essence of this algorithm is to search for the final hash, the value of which must be less than a certain threshold value that is known to the network. The reward in this case goes to the winner of the PoW “game”. The approach has several disadvantages, the main one being high energy consumption. Another example of the economic consensus algorithm is PoS (Proof-of-Stake). With this approach, votes are cast not for computing power, but for coins. For now, PoS continues to be under wide discussion, since this consensus algorithm has a number of open questions and problems. As to the mathematical direction, it includes the BFT consensus algorithm, which operates on the classic and facetious “Byzantine Generals Problem.”
