Ledger Verifiable Pruning System

Abstract

The present invention discloses a verifiable pruning system for a ledger, which includes a skewed Merkle tree generation module. The skewed Merkle tree generation module includes the root hash value R of a previous subtree according to a linked list method n‑1 in a data block T n and hashes the data block T n‑1 including the root hash value R n to calculate h(T n ). The calculated h(T n ) and the root hash value R of the previous subtree n‑1 are summed and then hashed to calculate h(h(T n )|R n‑1 ). The calculated h(h(T n )|R n‑1 ) is sequentially added to each node of a binary Merkle tree structure to expand and generate a skewed Merkle tree. According to the above ledger verifiable pruning system, the ledger structure is configured as a skewed Merkle tree, which only stores and manages the latest data and verifies the authenticity of transactions submitted by another node, thereby having the effect of minimizing and maintaining the increase in the ledger size. In particular, it is configured to manage a distributed ledger by converting from a skewed Merkle tree to an upgraded h-skewed Merkle tree, which has the effect of greatly reducing the size of proof data for verification that increases over time. And while reducing the size of proof data for verification, the authenticity of old data from several years ago can be verified through fewer arithmetic steps, thereby having the effect of further improving the verification speed.

Claims

1. A general ledger verifiable pruning system, wherein the general ledger verifiable pruning system is applied to a blockchain, It is characterized in that The h-skew Merkle tree generation module is included. The h-skew Merkle tree generation module is used to generate a new data block T according to a linked list. n Add to the existing skewed Merkle tree and hash the root value R of the existing skewed Merkle tree n-1 Contained in data block T n In the above, the root hash value R n-1 Data block T n Hash to calculate h(T n ), the calculated h(T n ), the root hash value R of the existing skewed Merkle tree n-1 With jump link R n-(基数^偏移量) After summing, hashing is performed to calculate h(h(T n )|R n-1 |R n-(基数^偏移量) ), the calculated h(h(T n )|R n-1 |R n-(基数^偏移量) ) are added to each node of the binary Merkle tree structure in turn, thereby expanding and generating an h-skew Merkle tree, The above jump link R n-(基数^偏移量) is the root hash value of the skewed Merkle tree at a specified time point in the past in the h-skewed Merkle tree, The value of the cardinality is the shortest distance of the jump link preset in order to allocate the jump link to each specified interval. The above offset value is the remainder of the current node position n divided by the base value. The distance of the above jump link is calculated by the cardinality ^ The offset value is calculated, where the base ^ The offset is expressed as the base raised to the power of the offset.

2. The ledger verifiable pruning system of claim 1, It is characterized in that The h-skew Merkle tree generation module is configured to move towards the offset + (radix ^ The above jump link is assigned to each node of offset)*k, where the above k consists of a positive integer.

3. The ledger verifiable pruning system of claim 1, It is characterized in that It also includes a node authenticity verification module, which verifies the past specified data block T k Is it included in the above h-skew Merkle tree? k and the specified root hash value h(T i ) perform hash value operations in sequence to calculate the latest root hash value of the h-skew Merkle tree, and compare the calculated latest root hash value with the previously known latest root hash value R n Consistent, to verify the above T k The truth of the above h(Ti), k <i<=n。 4. The ledger verifiable pruning system of claim 3, It is characterized in that The node authenticity verification module is configured to verify whether the hash value R exists in the h-skew Merkle tree according to the following steps: y or data block T y : Step 1): From the latest root hash R head Based on the links within a specified distance to the past time point, search for links related to R y A jump link or link that exists at the earliest time in the past or in a future link; Step 2): Based on the jump link or the hash value of the link that existed at the earliest time point in the past retrieved above to the link within a specified distance in the direction of the past time point, retrieve the link that is related to R y A jump link or link that exists at the earliest time in the past or in a future link; Step 3): Repeat the process of step 2) until the above R is reached y ; Step 4): Using the above T y , for the jump links or sets of links repeatedly retrieved in the above steps 2) and 3), calculate the root hash in the future direction in sequence; as well as Step 5): Compare the final calculated root hash value with the above R head If the comparison results are the same, then verify the above hash value R y Or data block T y Exists in h-skew Merkle trees.

5. The ledger verifiable pruning system of claim 4, It is characterized in that The distances specified above are base numbers.

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