Method for selecting consensus node using nonce and method and apparatus for generating blockchain using the same

1. A method for generating a blockchain, comprising:

selecting, by a first master node that generated a first block, second candidate nodes from a node pool according to a consensus node selection scheme using a nonce;

generating, by each of the selected second candidate nodes, a second candidate block; and

selecting, by the first master node, a second master node from the second candidate nodes based on a result of a vote for the second candidate blocks, which is taken by first candidate nodes,

wherein the selecting the second candidate nodes comprises calculating a distance corresponding to a result of comparison of a coupon with a threshold value,

wherein a candidate block generated by the second master node is locked as a second block in the blockchain, and

wherein each of the second candidate nodes records the distance corresponding thereto and a digital signature for checking whether the distance issued in a candidate block is legitimate and transmits the candidate block to another node.

2. The method of claim 1 , wherein the nonce is generated using a head hash value of a generated block and a unique value possessed by each node.

3. The method of claim 2 , wherein the unique value is a private key or a value acquired from a nonce pool.

4. The method of claim 3 , wherein selecting the second candidate nodes further comprises comparing the coupon, which is at least a portion of the head hash value, with the threshold value.

5. The method of claim 1 , wherein:

each of the second candidate nodes performs a checking process through a nonce chain in order to check the distance corresponding to the node and whether the distance issued is legitimate.

6. The method of claim 1 , further comprising:

announcing, by each of the second candidate nodes, the coupon and the calculated distance to the node pool or the first candidate nodes.

7. The method of claim 6 , wherein each of the first candidate nodes sorts the second candidate nodes based on a result of sorting the calculated distances.

8. The method of claim 7 , wherein each of the first candidate nodes transmits the collected distances of the second candidate nodes to the first master node.

9. The method of claim 1 , wherein a number of second candidate nodes is used as a population parameter of the vote taken by the first candidate nodes.

10. The method of claim 1 , wherein the distance values of the second candidate nodes are used in the vote taken by the first candidate nodes.

11. The method of claim 1 , wherein, in order to use the consensus node selection scheme as a private consensus mechanism, a node that is selected as a node to generate a candidate block is shared through the node pool, and predetermined nodes are registered in the node pool.

12. The method of claim 1 , wherein, in order to use the consensus node selection scheme as a public consensus mechanism, all of participation nodes are allowed to participate in the node pool.

13. A method for generating a blockchain, comprising:

selecting, by a first master node that generated a first block, second candidate nodes from a node pool according to a consensus node selection scheme using a nonce;

generating, by each of the selected second candidate nodes, a second candidate block;

selecting, by the first master node, a second master node from among the second candidate nodes based on a result of a vote for the second candidate blocks, which is taken by first candidate nodes;

performing a hash operation by taking a hash value of a previous block and a digital signature signed with a private key of a participation node or a value acquired from a nonce chain as input;

comparing a coupon, which is configured with at least a portion of a result of the hash operation, with a threshold value; and

selecting the participation node as a candidate node for generating a block based on a result of comparison,

wherein each of the second candidate nodes performs a checking process through a nonce chain in order to check a distance corresponding to the node and whether the distance issued is legitimate, and

wherein the second candidate block generated by the second master node is locked as a second block in the blockchain.

14. The method of claim 13 , wherein a node pool is predetermined or includes all nodes.

15. The method of claim 13 , wherein a node pool is classified into two or more groups based on the result of comparison.

16. The method of claim 15 , wherein:

the two or more groups include a pass group and a fail group, and

the pass group and the fail group have a binomial distribution characteristic.

17. The method of claim 15 , wherein a mean and a variance of nodes to be selected are calculated according to a specific probability distribution.

18. An apparatus for generating a blockchain, comprising:

at least one processor; and

memory configured to store at least one instruction executed by the at least one processor,

wherein the at least one instruction is executed by the at least one processor such that a hash value of a block generated by a first master node is calculated, such that second candidate nodes are selected using a result of hashing a value acquired by digitally signing the calculated hash value or a result of hashing the hash value of the block generated by the first master node and a value acquired from a nonce chain, such that the second candidate nodes take a vote in order to lock a second master block, among second candidate blocks, and such that the first master node locks the second master block,

wherein each of the second candidate nodes performs a checking process through the nonce chain in order to check a distance corresponding to the node and whether the distance issued is legitimate, and

wherein, based on a result of the vote by the nodes that generated the second candidate blocks, the first master node locks a second candidate block in the blockchain, that presents a minimum or maximum distance approved by more than a threshold number of the nodes.