Constellation Symbol Transforms for Physical-Layer Eavesdropping Resistance
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Solution Overview
Problem
Existing communication systems are vulnerable to eavesdropping and reveal sender and receiver proximity through modulation format detection, compromising security at the physical layer.
Innovation Solution
Transforming constellation symbols using randomly generated keys to obscure data points in the I-Q plane, applying rotations, remappings, and magnitude adjustments to secure communication over unsecured channels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional modulation formats are used for data transmission, then communication efficiency is maintained, but security is compromised due to vulnerability to eavesdropping and modulation format detection
Solution Approach 1:
The patent transforms constellation symbols by changing their parameters (I-Q coordinates) using coordinate transformation functions. Each data point (c, d) is transformed to new coordinates (c', d') using functions Fc and Fd that depend on secret keys, thereby altering the physical layer characteristics while maintaining the underlying data integrity and improving security against eavesdropping
Solution Approach 2:
The patent applies coordinate transformation to constellation symbols before transmission. By pre-transforming the I-Q coordinates using secret key-dependent functions, the system prepares the signal in advance to resist eavesdropping and modulation format detection, rather than applying security measures after interception
2Reliability
If coordinate transformation with multiple keys is applied to each data point, then security against eavesdropping is enhanced, but computational complexity increases
Solution Approach 1:
The patent divides the coordinate transformation into separate independent functions for the real component (Fc) and imaginary component (Fd). This segmentation allows each component to be processed independently using its own secret key, reducing the overall computational complexity compared to a unified transformation approach while maintaining security
Solution Approach 2:
The patent applies different secret keys (first secret key for real component, second secret key for imaginary component) to different parts of the constellation symbol. This local differentiation enhances security by ensuring that compromise of one key does not reveal the other, while keeping the computational burden manageable through localized transformations
3Reliability
If I-Q coordinate transformation is applied to constellation symbols, then security at the physical layer is improved, but the complexity of signal processing increases
Solution Approach 1:
The patent replaces traditional cryptographic mechanisms (operating at higher OSI layers) with a physical layer mechanism based on I-Q coordinate transformation. By substituting mathematical/crypto operations with signal-level coordinate transformations, the system achieves security directly at the transmission medium level, reducing the need for complex higher-layer encryption protocols
Data Source
AI summary
A computing device transforms symbols in a network constellation and securely transmits data over an unsecured communications channel. The computing device obtains data points encoded in a constellation of predefined symbols. Each data point is represented by a magnitude and angle corresponding to one of the predefined symbols. The computing device obtains a set of keys and generates a first transformation for a first data point based on a first key. The first transformation applies a first rotation that adjusts the angle of the first data point based on the first key. The computing device generates a first transformed data point by applying the first transformation to the first data point and transmits a signal including the first transformed data point.