Group Key Management for Mobile Devices
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Solution Overview
Problem
Existing group key management systems face challenges in securely updating and distributing group keys to mobile devices, particularly when devices are in motion and outside the coverage of a base station, leading to potential security vulnerabilities and communication inefficiencies.
Innovation Solution
A method and apparatus that utilize a Group Controller (GC) or Key Distribution Center (KDC) to manage and encrypt group keys, allowing mobile devices to receive updated keys from base stations within their coverage or from other devices, using a bilinear map and cryptographic techniques to ensure secure key verification and transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a mobile device receives group key from a base station, then the device can obtain updated group key, but security is insufficient when base station changes and the device cannot receive key when no base station is nearby
Solution Approach 1:
The patent introduces a key chain structure where intermediate keys (first group key, second group key) act as mediators between the key distribution center and mobile devices. When a device cannot connect to a base station, it can still obtain the latest group key through other group members who have received it, ensuring continuous key updates regardless of base station availability.
Solution Approach 2:
The patent implements dynamic key management where group keys are continuously updated and redistributed among group members. The system adapts to changing network conditions by allowing devices to receive keys from multiple sources (base station or other group members) and maintains key validity through time-stamped key chains that adjust to device mobility and base station changes.
2Reliability
If group key is updated frequently to maintain security, then security is improved, but communication overhead and operational burden increase
Solution Approach 1:
The patent employs preliminary key generation and distribution through a key chain structure. The key distribution center pre-generates multiple group keys (first group key, second group key) and distributes them in advance to base stations and group members. This allows devices to obtain keys proactively before they are needed, reducing the frequency and intensity of key update communications while maintaining continuous security.
Solution Approach 2:
The patent uses key copying and redistribution among group members. Instead of the key distribution center directly communicating with each device for every key update, it copies keys to selected group members who then redistribute them. This copying mechanism reduces communication overhead by leveraging existing group members as key distribution nodes.
Data Source
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AI summary
Provided is a method for managing a group key in a key distribution center. The method includes: receiving a key request from a mobile device; generating a private key for the mobile device using information about a withdrawal time included in the key request; generating a public key and a verification key for the mobile device; and transmitting at least one key including the generated key to the mobile device.