Re-encrypted Data Verification Using Nested Formula
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional re-encryption techniques fail to enable the decryption apparatus to verify the original intended recipient of re-encrypted data, making it difficult to identify the source of information leakage.
Innovation Solution
A re-encryption system comprising an encryption apparatus, a re-encryption key generation apparatus, and a decryption apparatus, where the decryption apparatus uses a verification formula to determine the original public key used for encryption, allowing it to verify the intended recipient of the re-encrypted data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If re-encryption is performed without including verification information, then re-encryption efficiency is improved, but the ability to verify the original recipient is lost
Solution Approach 1:
The verification formula is nested within the re-encrypted data structure itself. The re-encrypted data includes both the encrypted content and the verification formula that proves the original recipient's identity, allowing verification without separate processes or additional communication rounds.
Solution Approach 2:
The verification formula is generated and embedded during the re-encryption process itself, before the data is transmitted to the decryptor. This preliminary inclusion of verification information eliminates the need for subsequent verification steps, maintaining efficiency while ensuring reliability.
2Reliability
If verification information is added to re-encrypted data, then verification capability is improved, but data size increases
Solution Approach 1:
The verification formula utilizes cryptographic parameters that are derived from existing keys and values already present in the re-encryption system. By changing the representation form rather than adding entirely new data elements, the verification capability is enhanced with minimal increase in data size.
3Measurement precision
If complex verification formulas are used, then verification accuracy is improved, but computational complexity increases
Solution Approach 1:
The verification formula acts as an intermediary mathematical structure that bridges the re-encrypted data and the original public key. Instead of directly comparing complex cryptographic primitives, the formula provides an intermediate verification step that is computationally more efficient while maintaining high accuracy in identifying the original recipient.
Data Source
AI summary
In a decryption apparatus according to an embodiment, a holding device pre-holds a verification formula. A determination device performs a calculation based on the verification formula read from the holding device by substituting, into the verification formula, the part of the re-encrypted data received from a re-encryption apparatus and the public key of a re-encryption key generation apparatus and the private key of the decryption apparatus, to determine whether or not the verification formula holds true. An output device outputs verification success when a result of the determination indicates that the verification formula holds true.