Secret Key Generation via Channel Codebooks for Secure Wireless
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Solution Overview
Problem
Existing communication systems face challenges in securely generating and continuously providing secret keys, especially in wireless channels, due to high implementation complexity and security vulnerabilities from eavesdropping and brute force attacks.
Innovation Solution
A method and apparatus for generating a secret key based on channel state information using pilot signals and channel codebooks, where communication nodes estimate channel states, generate and synchronize channel codebooks, and use these to create and share secret keys for secure data transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a secret key is continuously provided through a wireless channel, then secure communication can be maintained, but security is deteriorated by stealing or leakage of the secret key by eavesdropping
Solution Approach 1:
The patent applies preliminary action by pre-generating and storing multiple secret keys in both the base station and terminal before communication begins. When channel conditions change, the system can switch to a pre-prepared key without transmitting new keys over the wireless channel, thus avoiding eavesdropping risks while maintaining secure communication continuity.
Solution Approach 2:
The patent utilizes parameter changes by monitoring channel quality indicators (CQI) and switching between different secret keys based on channel conditions. When the channel state changes beyond a threshold, the system transitions from one secret key to another, ensuring that eavesdroppers cannot continuously intercept the same key while maintaining secure communication adaptability.
2Ease of operation
If a predefined irrational number is used as the secret key to solve the problem of providing an infinitely long secret key, then the secret key length problem is solved, but the computational amount is gradually increased making it not continuously usable
Solution Approach 1:
The patent segments the secret key management into multiple discrete keys stored in a sequence. Instead of using one long irrational number that requires continuous computation, the system divides the key space into multiple manageable segments (keys) that can be selected and switched based on channel conditions, reducing computational burden while solving the key length problem.
Solution Approach 2:
The patent employs multiple finite secret keys that can be disposed of and switched to the next key in the sequence. Each key has a limited lifespan determined by channel condition changes, replacing the need for an infinitely long key. This approach uses simpler, finite keys that are computationally efficient while maintaining security through periodic key exhaustion and switching.
3Reliability
If quantum communication scheme is used to provide secret key to solve the problem of secret key leakage, then security is improved, but the implementation difficulty is very high as it is still in laboratory stage
Solution Approach 1:
The patent applies self-service by enabling the communication terminals and base station to autonomously generate and manage multiple secret keys locally without requiring external quantum communication infrastructure. The system self-manages key selection and switching based on channel conditions, achieving quantum-like security through classical means while avoiding the high implementation complexity of actual quantum communication systems.
4Reliability
If a secret key is provided to the transmitter and receiver, then secure communication is achieved, but an infinitely long secret key should be provided which is impractical
Solution Approach 1:
The patent implements periodic action by using a sequence of finite secret keys that are consumed and switched periodically based on channel condition changes. Instead of requiring an infinitely long key, the system cycles through multiple keys in a predetermined sequence, with each key valid for a specific period or channel condition range, thus providing practical key management while maintaining security.
Data Source
AI summary
An operation method of a first communication node in a communication system may comprise estimating a channel state between the first communication node and a second communication node based on a pilot signal received from the second communication node; generating a first channel codebook based on the estimated channel state; transmitting information of the first channel codebook to the second communication node; receiving a response indicating whether the first channel codebook is to be used from the second communication node; when the response is an ACK indicating that the first channel codebook is to be used, generating a first secret key by using the first channel codebook; and transmitting data encrypted using the first secret key to the second communication node.