Broadcast Encryption Tag Generation Reducing Transmission Overhead

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Solution Overview

Problem

Broadcast encryption systems face high transmission overhead due to large tag sizes, which impact efficiency in securely transmitting encrypted information to authorized users while revoking unauthorized nodes.

Innovation Solution

A tag generation method in a broadcast encryption system that reduces tag size by utilizing node IDs and group IDs to efficiently identify revoked nodes, generating a tag list through a layered structure, and combining node path IDs with group IDs to minimize transmission overhead.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional tag generation methods are used in broadcast encryption systems, then authorized users can be identified and unauthorized nodes can be revoked, but the tag size becomes large causing high transmission overhead

Engineering Contradiction:
Improveauthorization accuracyVSAvoidtransmission overhead
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent segments the tag into multiple components: a first tag part containing group identification information and a second tag part containing node path information. This segmentation allows efficient encoding by separating the group-level identification (which is reused) from the specific node identification, thereby reducing the overall tag size while maintaining authorization accuracy.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a hierarchical dimension to tag generation by using a layered structure where nodes are organized in levels. Instead of using flat, exhaustive node identifiers, the system uses path information from the root to the node in the hierarchy, reducing the tag size from potentially representing all nodes to only the necessary path components, achieving up to 65 times reduction in tag size.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If comprehensive node identification is used to ensure all revoked nodes are identified, then authorization reliability is maintained, but tag size increases reducing transmission efficiency

Engineering Contradiction:
Improverevocation accuracyVSAvoidtransmission efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent merges the group identification information with the node path information in a unified tag structure. By combining these elements, the system achieves comprehensive node identification (ensuring all revoked nodes are accurately identified) while minimizing tag size through efficient encoding, thereby maintaining revocation accuracy and improving transmission efficiency simultaneously.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP2547035B1Tag generation method in broadcast encryption system
Publication Date: 2018.10.31 SAMSUNG ELECTRONICS CO LTD
  • EP2547035B1 patent drawingFigure 1~3
  • EP2547035B1 patent drawingFigure 4~5

AI summary

A tag generation method for generating tags used in a broadcast encryption system is provided. The method includes detecting at least one revoked leaf node; setting a node identification (node ID) assigned to at least one node among nodes assigned node IDs at a layer 0 and to which the at least one revoked leaf node is subordinate, to a node path identification (NPID) of the at least one revoked leaf node at the layer 0; generating a tag list in the layer 0 by combining the NPID of each of the at least one revoked leaf nodes at the layer 0 in order of increment of node IDs of the corresponding at least one revoked leaf nodes; and generating a tag list in a lowest layer by repeatedly performing the setting and generation operation down to the lowest layer.