Blockchain Resource Access with Distributed Key-Share Verification

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Solution Overview

Problem

Existing systems lack secure methods to control access to and verify the integrity of digital assets on blockchain networks, particularly in scenarios where documents need to remain confidential until all participants have submitted their contributions and ensure that the documents are not altered.

Innovation Solution

A method involving nodes sharing private key shares to encrypt documents using collaborative public keys, with transactions on a blockchain network to verify submission and integrity, allowing synchronized access only when all nodes reveal their key shares.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If documents are stored in electronic form on a blockchain network, then accessibility and verification are improved, but security and integrity control deteriorate due to risks of unauthorized access and alteration

Engineering Contradiction:
ImproveaccessibilityVSAvoidsecurity
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The private key is segmented into multiple private key shares distributed to different nodes in the blockchain network. No single node possesses the complete private key, preventing unauthorized access while maintaining collective control over the encrypted documents.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A collaborative public key acts as an intermediary between the encrypted documents and the private key shares. The collaborative public key enables encryption without requiring any single node to have access to the complete decryption capability, thus securing the documents while maintaining accessibility.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Adaptability or versatility

If all nodes have access to decrypt encrypted documents, then collaboration is improved, but confidentiality deteriorates as documents may be accessed before all participants have submitted

Engineering Contradiction:
ImprovecollaborationVSAvoidconfidentiality
Core Design Contradiction:
Adaptability or versatilityVSLoss of information

Solution Approach 1:

The decryption capability is segmented across multiple nodes through private key shares. Each node holds only a portion of the key material, and collectively they can decrypt documents only when all nodes have contributed their shares, ensuring confidentiality until the submission deadline.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Documents are encrypted with the collaborative public key in advance, before any node has access to the complete decryption capability. This preliminary encryption ensures that even though all nodes can participate in the collaboration, they cannot access the document contents until the collective private key is assembled from all shares.

Inventive Principle:
Principle #10Preliminary action

3Loss of information

If traditional sealed envelope methods are used, then confidentiality is improved, but ease of operation and modernization deteriorate

Engineering Contradiction:
ImproveconfidentialityVSAvoidmodernization
Core Design Contradiction:
Loss of informationVSEase of operation

Solution Approach 1:

The mechanical sealed envelope system is replaced with cryptographic encryption using public-key infrastructure. The collaborative public key and private key shares provide digital equivalents of sealing, enabling confidentiality through mathematical rather than physical means, thus modernizing the process while maintaining security.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Device complexity

If centralized trust models are used, then simplicity is improved, but security and reliability deteriorate due to single point of failure

Engineering Contradiction:
ImprovesimplicityVSAvoidsecurity
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The centralized trust model is segmented into a distributed trust model where no single entity controls the complete private key. Private key shares are distributed across multiple independent nodes, eliminating the single point of failure while maintaining a relatively simple operational framework through automated cryptographic protocols.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The collaborative public key serves as a mediator that enables trustless collaboration. Nodes can encrypt documents and verify integrity without needing to trust any single participant, as the cryptographic system itself enforces the security model, simplifying the trust requirements while enhancing reliability.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3763098B1Methods and systems for controlling access to, and integrity of, resources on a blockchain
Publication Date: 2025.08.06 NCHAIN LICENSING AG
  • EP3763098B1 patent drawingFigure 1
  • EP3763098B1 patent drawingFigure 2
  • EP3763098B1 patent drawingFigure 3A

AI summary

A method and devices for verifying a digital resource by a plurality of node devices in a blockchain network. The plurality of nodes have respective private key shares, where a collective private key of a collective private-public key pair is based on a set of the respective private key shares, and where each node has a nodal private-public key pair. The digital resource may be encrypted using a digital resource crypto public key, the digital resource crypto public key including combination of a nodal public key and a collective public key. The digital resource may be submitted to a repository system by broadcasting a commitment transaction and a subsequent reveal or rescind transaction of a commitment channel, the commitment channel formed between a respective node and a principal node. Decrypting the encrypted digital resource is based on retrieving private key share contributions from the plurality of nodes participating in verifying the digital resource.