Hierarchical Predicate Encryption Key Size Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Hierarchical predicate encryption (HPE) schemes for inner products face inefficiencies due to large key sizes, affecting operational efficiency.
Innovation Solution
A cryptographic processing system that uses multiple spaces to construct a hierarchical structure, where attribute information is embedded in basis vectors and predicate information is embedded in decryption keys, enabling pairing operations and key delegation to reduce key sizes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If HPE scheme for inner products uses one large space, then cryptographic functionality is achieved, but key sizes become large
Solution Approach 1:
The patent divides the cryptographic system into multiple separate spaces (first space and second space) instead of using one large space. Each space handles specific cryptographic operations, allowing keys to be segmented and stored separately, thus reducing the overall key size while maintaining cryptographic functionality.
Solution Approach 2:
The patent transitions from a single-dimensional large space to a multi-dimensional structure with multiple separate spaces. By distributing cryptographic elements across different spaces (dimensions), the system achieves the same functional capacity with reduced key sizes in each individual space.
2Reliability
If large key sizes are used, then cryptographic security is maintained, but operational efficiency deteriorates
Solution Approach 1:
By segmenting the cryptographic system into multiple spaces with dedicated functions, operations can be performed in smaller, more efficient units. This segmentation maintains security through proper distribution of cryptographic elements while improving operational efficiency by avoiding the overhead of manipulating large keys.
Solution Approach 2:
The patent introduces pairing operations as intermediaries that enable secure cryptographic operations without requiring large keys to be directly manipulated. These pairing operations act as mediators that maintain security requirements while improving operational efficiency.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
It is an object to provide hierarchical predicate encryption (HPE) for inner products with enhanced efficiency of operations and so on. A cryptographic processing system 10 includes a key generation device 100, an encryption device 200, and a decryption device 300. The key generation device 100 generates, as a decryption key skL, a vector in which predicate information v→t is embedded in a basis vector of a basis B*t for each integer t of t = 1, ..., L. The encryption device 200 generates, as a ciphertext ct, a vector in which attribute information x→t is embedded in a basis vector of a basis Bt for at least some integer t of t = 1, ..., L. The decryption device 300 performs a pairing operation on the decryption key skL generated by the key generation device 100 and the ciphertext ct generated by the encryption device 200, and decrypts the ciphertext ct.