BLOCK CHAIN CONSENSUS METHOD
Technical Field
The invention related to a consensus method that is utilised in all areas where blockchain is used, provides security and flexibility for the applications requesting dynamic approval rate.
Prior Art
Blockchain is a system that enables the management of any data flow and is managed by a network established between nodes (server/client) that do not have a central authority while managing the data flow. A "node" is a device where transactions take place and are recorded. A blockchain is a system that allows groups of users to work together. In a blockchain containing different user groups, consensus algorithms are used to achieve consensus. Consensus algorithms are algorithms that allow a certain data to be agreed on distributed processes or systems. Each consensus algorithm eliminates different problems.
Existing consensus algorithms are called Proof of Work (PoW), Proof of Stake (PoS) and Proof of Authority (PoA).
The disadvantages of the above-mentioned consensus methods according to the state of the art are as follows;
- In blockchain applications the consensus methods decide addition of a new block to the chain. Existing consensus algorithms forblockchain applications require solution of a mathematical problem which generally demand a large amount of processing power and time.
- As the solution of a mathematical problem requires large amount of computational power, the devices for the consensus implementation need to have enough procession power which also requires large amount of energy consumption. The fact that the computational power (computational cost) for these mathematical operations is not lightweight prevent application of blockchain technology from the environments consisting of resource-constrained devices. This is one of the factors that limits the use of consensus algorithms hence blockchain technology. - Known consensus algorithms depend on processor power. Since processor power are the most important factors for the devices used in especially proof-of-work and proof-of-stake consensus algorithms, the consensus of a certain group of users in the system might take over the system with only 51% of the required computing power.
In the United States patent document US2022076518A1 of the state of the art, the blockchain-based system for selecting a winner among weighted candidates is mentioned. This system comprises a server consisting of a secret voting smart contract consisting of a ballot paper and multiple candidates, each with a certain weighted value, and a digital wallet that has a digital identity and can communicate with the server. In order to add a new block to the existing blockchain, all transactions in the blockchain must be verified and go through a consensus process. When the administrator (310) initiates voting, the secret ballot smart contract (320) is activated in a blockchain network (360), allowing validator nodes (365) (which are proof-of-stake or proof-of-authority nodes selected by the administrator from among the nodes included in the blockchain network) to access the secret ballot smart contract. When voters (340) cast their votes through the secret ballot smart contract (320), validator nodes (365) verify the voting data, and when a consensus is reached for all votes, the voting data is fully ready to be added to the blockchain as a new block. The consensus algorithm specified in the system is proof of stake. According to embodiments of the invention, an appropriate number of members are registered as voters (340), selected under their consent from among the members registered on the admin server (310).
In the Chinese patent document CN 109639430 A, of the state of the art, a secure, high-speed and lightweight blockchain system and method is mentioned. Here, the system includes an initialisation module, a registration-processing module and a block creation module. The initialisation module runs when the system is initialised and is used to set the relative parameters of the blockchain system and to deploy a point-to-point network. Thus, the system function is initialised and reaches a steady state through block creation in the first phase. The initialisation module has a dynamic threshold rate of miner confirmation. The registration-processing module is used to call the user registration function when a user joins the system, generate the user's public/private key pair, send the trading card to the blockchain network, verify the validity of the trading card through the network node, and continuously broadcast the legal transaction to the entire network. The block generation module is used to determine the miner candidate set of an existing block according to the trading participant address in a specific block in a target blockchain system assigned by the system. In addition, a candidate in the miner candidate set (S={So,...Sn}) can create a new block using the consensus mechanism.
In the United States patent document No. US20170075941A1, of the state of the art, a method to be used to reach consensus to add a data block to a distributed ledger distributed through an inter-user network is mentioned. A predetermined condition calculated using previous data from the distributed ledger and a block of data calculated using a hash of a public key and a unique address identifier are added to the distributed ledger.
In the United States patent document numbered US2021390549A1, which is in the known state of the art, blockchain creation systems and methods are mentioned. After the verification process, a new block is added to the block chain. This system includes a memory, a block chain, a set of nodes, a set of validators, a set of miners and a consensus protocol. The memory may have a block data structure representing a transaction for an entity with an identifier and at least one verifiable property. The consensus protocol includes rules such as taking the stake at risk from validators, providing reputation points to validators, verification of the verifiable property of the asset by validators, cryptographic verification by miners, adding the new block to the blockchain, providing rewards to miners, and distributing a copy of the blockchain to each node.
In the Chinese patent document CN112541763 A of the state of the art, the block consensus approval method for the blockchain manager is mentioned. It is mentioned that if the consensus approval is greater than the calculated threshold value, it is possible to proceed to the next block.
However, the consensus methods in the sample patent documents do not include a blockchain consensus method in which the approval rate can be changed when necessary, the need for processing power is small, and the increase in the number of users participating in the blockchain does not affect the processing load, thus providing scalability. Therefore, there is a need to develop an inventive blockchain consensus method to address the disadvantages in the current situation. Objects of the Invention
The object of the present invention is to provide a consensus method that provides a flexible proof-of-stake algorithm that allows the approval rate, which forms the basis of the policy that will provide consensus on the block to be added to the blockchain, to be changed when necessary.
Another object of the present invention is to realise a blockchain consensus method that provides security by requiring the number of miner and validator nodes required for consensus to be equal, and lightweight by reducing the need for processing power.
Another aim of the present invention is to realise a blockchain consensus method that determines the consensus policy in case the number of users in the blockchain system increases, without compromising security and lightweightness according to the number of new users, and provides scalability by determining the approval rate.
Another object of the present invention is the realisation of a blockchain consensus method that enables the determination of a consensus condition that can theoretically be adapted to any scenario when needed.
Detailed Description of the Invention
Block chain consensus method according to the invention comprises the process steps;
- determining the number of users in the blockchain network and labelling this number with k,
- setting an approval rate (InApprate (=initial approval rate)) during the creation of the blockchain, which can be changed if necessary,
- determining the (InApprate)x(k+l) dimensional vector space Wk from which the keys of k users in the system will be obtained in order to apply the determined approval rate,
- distributing the keys to be used in the approval phase from the vector space for the group G with k users to whom the specified vector space is allocated, (The key for each user is defined as a randomly selected vector from the specified vector space (Wk).)
- the necessary condition for the approval phase; obtaining the perpendicular projection vector (projwk f = g) of a random vector f into the vector space Wk and obtaining the image (g(a) value) of a randomly selected number (a value) from the range defined by the obtained perpendicular projection vector (g) under that projection vector,
- finding the value (projwk f = g and g(a) values) determined in the approval phase using a randomised vector f and a sufficient number of user keys based on the miners' approval policy and approval rate determined for the consensus phase,
- comparing the result (Vrate (=verifier rate)) obtained by the verifier nodes by performing the steps performed by the miners with the result (Mrate (=miner rate)) found by the miners, again based on the approval policy and approval rate determined in the verification phase,
- reaching a consensus and adding the block to the chain if the values (Vrate, Mrate) found by miners and validator nodes are equal to g(a),
- returning to the approval stage and repeating the processes if the compared values are not the same.
In any system where block chain technology is used, it is necessary to obtain the approval of the users at any rate. Thanks to the developed consensus method in question, the need for processing power is reduced.
In the initialisation and registration phase of the developed method, firstly, a group G consisting of k users {Ui, U2, U3, ... Uk} is created in which the blockchain is used. An open source application that eliminates the need for a central authority for the progress of the blockchain is running. In this open source application, the consensus is realised with the approval rate determined by the users in the system. When the block chain is created, an approval rate (InApprate (=initial approval rate)) is determined, which k existing users agree on, which tells what percentage of users' approval is required for a block to be added to the chain, and which can change according to the consensus policy when necessary. This approval rate (InApprate) can be changed depending on any situation and demand. In order to apply the specified approval rate, a vector space (Wk) is determined in which the key for the group G containing k users in the system will be obtained. According to the compromise method based on the specified approval rate, a (InApprate)x(k+l) dimensional vector space Wk is created. This vector space (Wk) is created as a subspace of the infinite dimensional universal inner product space and users in the system are given a random vector, i.e. keys, from this subspace. The user group to which the relevant vector space is allocated is allocated keys from that space to be used in the approval phase. In the approval phase of the developed method, the condition required for the approval of a transaction is determined as finding the vertical projection vector (g) of a random vector f to the vector space Wk, i.e. projwk f = g, and finding the image (g(a) value) of a number (a value) randomly selected from the range defined by the obtained vertical projection vector (g) under that projection vector.
In the consensus phase of the proposed method, miners, who are responsible for finding the desired result, need to find the value (projwk f = g and g(a) values) determined in the consensus phase by using a randomly published vector f and a sufficient number of user keys (a random vector selected from the vector space) based on the approval policy and approval rate. Similarly, the operations performed by miners are also performed by users, called validator nodes. Verifier nodes also need to find the value of projwk f=g and g(a). In finding this value, the approval of a sufficient number of users in the system and the vectors owned by the approving users are transmitted to the user called validator nodes and the subspace Wk is created. The validator nodes find the value (projwk f = g and g(a) values) determined in the approval phase by using a sufficient number of user keys (a random vector selected from the vector space). Each user in the blockchain has a vector from the relevant vector space. This vector space can be created by combining as many users as the number of dimensions of this vector space. Therefore, this vector space can be constructed by combining the number of verifier nodes (any users in the chain) up to the number of dimensions of the vector space. Mathematically, the correctness of this situation can be explained as follows: Assuming that W is an n-dimensional subspace of an infinite dimensional universal space, the probability that n randomly chosen vectors from W are linearly dependent is negligibly small. Therefore, in the case where each user has a random vector, the space W can be formed by combining the vectors of any n users.
In the verification phase of the developed method, based on the approval policy and approval rate, the result (Vrate (=verifier rate)) obtained by the verifier nodes by performing the steps performed by the miners is compared with the result (Mrate (=miner rate)) values found by the miners. No operating power is required for the necessary operations (verification and mining) to be performed by the miner and verifier nodes that will provide Vrate and Mrate rates, and thus they can be randomly selected among the users in the system or they can participate voluntarily. In block chain systems, when a block is added to the chain, a random number is added to the previous block and the value under the hash function is calculated. The hash function result is expected to have a certain property. Based on the assumption that the hash function is unidirectional and random, the processing power required to find the desired result is very high. With this method, the dependency on this processing power is eliminated. The proportion of validation nodes (Vrate) that check that the addition of the new block is approved must be the same as the proportion of miners required (Mrate). In other words, the verification nodes and miner rate required for consensus will be equal to the approval rate (Vrate=Mrate=InApprate). The contribution of equal values of verification, miner and approval rates to security can be illustrated as follows: Even if the approval rate required to add a block is 26% (InApprate=26%), a person who captures 51% of the network processing power cannot take over the blockchain system due to the required ratio of miners (Mrate=26%) and validator nodes (Vrate=26%). If the values (Vrate, Mrate) found by miners and validator nodes are equal to g(a), the consensus is reached and the block is added to the chain. If the values of Vrate and Mrate are not the same, the process is repeated again in the confirmation phase.
In the scalability phase of the developed consensus method, if n new users join the existing system, n/2 linearly independent vectors are added to the vector set on the sub-vector space Wk. In this way, half of the users in the system are randomly provided with a new vector over the new vector space obtained. The other half can stay with the vector they had before. Thus, in the case that 50 more users join a block chain with 100 users, the approval phase is ensured to be realised with at least 51% user approval in the new extended space vector obtained by increasing the number of dimensions of the existing vector space by 25.
The block chain consensus method provides a consensus method that reduces energy consumption and increases the level of security. A flexible proof-of-stake algorithm is provided where the approval rate, which forms the basis of the policy that will provide a consensus on the block to be added to the block chain, can be changed when necessary. While reliability is ensured by the requirement that the number of miner and validator nodes required for consensus is equal, lightweight feature is provided by reducing the need for processing power. Thanks to the reduction of the need for processing power, a high-security consensus method is provided by providing consensus with the desired rate of approvals of the users in the blockchain, regardless of the computing power of the devices.
With this invention, the processing power required for the consensus algorithm has provided a method independent of the number of users in the system. In the event that the number of users in the blockchain system increases, scalability is achieved by determining the approval rate that determines the consensus policy without compromising security and lightweightness according to the number of new users. Here scalability is defined as the ability to increase the capacity of a blockchain network. The fact that there is no increase in the amount of transaction load per user allows the number of users participating in the blockchain to increase arbitrarily. Since the verification nodes and miner rate required for consensus are equal to the approval rate (Vrate=Mrate=InApprate), a person who captures 51% of the blockchain system cannot capture the blockchain system. Since the computation required by mining in the mathematical tool in the blockchain consensus method is very small compared to the existing consensus algorithms, an adaptable consensus method is provided for devices with limited power supply and limited processing (such as Internet of
Things devices).
The approval rate requirement can be adapted to a desired security model without the requirement of 51% or a similar requirement. Therefore, a consensus method is provided that can theoretically be adapted to any situation if needed.