Hybrid Key Exchange for Secure Offline Payment Data Transmission

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Solution Overview

Problem

Current data transmission methods face security risks due to shared encryption keys across client and server devices, and asymmetrical key algorithms result in lengthy encryption and decryption processes.

Innovation Solution

A data transmission method that generates an asymmetrical key pair with a different random number for each data request, using a key-agreement algorithm to create a shared symmetric key for encryption and decryption, ensuring the same key is used for both processes and maintaining security without exposing the complete key.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an asymmetrical key algorithm is used for encryption and decryption, then data security is improved, but encryption and decryption time increases

Engineering Contradiction:
Improvedata securityVSAvoidencryption and decryption time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent introduces a hybrid encryption scheme where asymmetrical keys serve as an intermediary to securely exchange symmetric keys. The asymmetrical key pair establishes a secure channel first, then a symmetric key is generated and exchanged through this channel. The symmetric key subsequently handles the actual data encryption/decryption, combining the security benefits of asymmetrical encryption with the speed of symmetric encryption.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If the same asymmetrical key pair is used for multiple data requests, then key generation complexity is reduced, but security decreases due to potential key leakage

Engineering Contradiction:
Improvekey generation complexityVSAvoidsecurity
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent implements dynamic key generation where a new asymmetrical key pair is generated for each data request rather than reusing a static key pair. This dynamic approach ensures that even if one key pair is compromised, other requests remain secure. The system adapts by continuously generating fresh keys while maintaining the same procedural complexity through automated key management.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent segments the encryption process by using separate asymmetrical key pairs for different data requests. Instead of using a single unified key pair for all communications, each request gets its own dedicated key pair, isolating security risks to individual requests while maintaining manageable complexity through systematic key management.

Inventive Principle:
Principle #1Segmentation

3Productivity

If a symmetric key is used for encryption and decryption, then encryption and decryption speed is improved, but security decreases if the key is intercepted

Engineering Contradiction:
Improveencryption and decryption speedVSAvoidsecurity
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent uses asymmetrical keys as an intermediary to securely transmit the symmetric key from the server to the client. The symmetric key itself never travels over the network in plaintext; instead, it is encrypted using the client's public key during transmission. This intermediary mechanism allows the system to benefit from the speed of symmetric encryption while maintaining the security advantages of asymmetrical key exchange.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3534565B1Data transmission method, apparatus and system
Publication Date: 2020.09.09 ADVANCED NEW TECHNOLOGIES CO LTD
  • EP3534565B1 patent drawingFigure 1A
  • EP3534565B1 patent drawingFigure 1B
  • EP3534565B1 patent drawingFigure 2~3

AI summary

Provided are a data transmission method, apparatus, and system. The method comprises: generating an asymmetrical key pair comprising a first public key and a first private key, sending a data request carrying the first public key to a server; receiving a ciphertext and a second public key sent by the server, wherein the second public key is a public key in an asymmetrical key pair obtained by the server, the asymmetrical key pair obtained by the server further comprises a second private key, and the ciphertext is information obtained by encrypting a seed parameter for generating an offline payment code using a shared key; the shared key is a key generated based on the second private key and the first public key using a preset key-agreement algorithm; and generating a shared key based on the first private key and the second public key using the key-agreement algorithm, and using the shared key to decrypt the ciphertext to obtain the seed parameter. The present application not only ensures data security throughout the entire transmission process, but also improves encryption and decryption efficiency.