Logic Gate Encryption Using Key-Configured Wiring Against Reverse Engineering
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Solution Overview
Problem
Current methods are inadequate for protecting proprietary information in hardware digital logic gates from reverse engineering, as sophisticated attackers can easily access and exploit secret encryption keys embedded in hardware, leading to exposure and theft of valuable IP.
Innovation Solution
Implementing a system where a logic key is used to determine the physical wiring of logic building blocks, encrypting the logic key, and using generic logic blocks that require a decryption key to function correctly, with secure storage and Physically Unclonable Functions (PUFs) to enhance protection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If encryption keys are embedded in hardware digital logic gates, then the system can perform secure encryption operations, but the keys become vulnerable to reverse engineering and unauthorized access
Solution Approach 1:
The patent segments the encryption system into multiple generic logic blocks that collectively implement the encryption function. Each block is configured based on bits of a logic key, so that the complete security function is distributed across multiple segments rather than concentrated in a single vulnerable key storage location. This segmentation prevents attackers from easily extracting the full encryption key through reverse engineering of individual blocks.
Solution Approach 2:
The patent introduces generic logic blocks as intermediary elements between the stored logic key and the encryption operation. These logic blocks act as mediators that transform the secret key bits into functional encryption logic without exposing the key itself. The intermediaries (logic blocks) perform the security-critical function while hiding the actual key material from potential attackers.
2Object-affected harmful factors
If generic logic blocks are used to implement encryption functions, then the system becomes resistant to reverse engineering, but the device complexity increases
Solution Approach 1:
The patent employs universal generic logic blocks that can be configured to perform different encryption functions based on their input parameters. Each generic logic block is designed to be multi-functional, capable of implementing various logic operations depending on how it is configured by the logic key bits. This universality reduces the need for multiple specialized components while maintaining security through configuration-based differentiation.
Solution Approach 2:
The patent changes the parameters (configuration bits) of generic logic blocks based on the logic key to create secure encryption functions. By varying the configuration parameters of identical logic blocks according to secret key bits, the system achieves functional diversity and security without increasing physical complexity. The same hardware structure adapts to different security requirements through parameter changes.
3Loss of information
If logic keys are used to determine physical wiring of logic blocks, then the actual function remains hidden even if reverse engineered, but the manufacturing process becomes more complex
Solution Approach 1:
The patent performs preliminary configuration of generic logic blocks during manufacturing based on the logic key. The wiring and configuration of logic blocks are predetermined and embedded during the manufacturing process, creating a fixed but hidden functional mapping. This preliminary action ensures that the true function is locked in before deployment, making it impossible to determine the actual encryption function through reverse engineering of the physical device.
Solution Approach 2:
The patent uses multiple copies of generic logic blocks that are configured identically or differently based on logic key bits. Instead of creating complex unique wiring for each function, the system uses replicated logic block templates that are selectively configured. This copying approach simplifies manufacturing by using standardized reusable blocks while still achieving function hiding through configuration variations.
Data Source
AI summary
Presented are systems and methods that allow hardware designers to protect valuable IP and information in the hardware domain in order to increase overall system security. In various embodiments of the invention this is accomplished by configuring logic gates of existing logic circuitry based on a key input. In certain embodiments, a logic function provides results that are dependent not only on input values but also on an encrypted logic key that determines connections for a given logic building block, such that the functionality of the logic function cannot be determined by reverse engineering. In some embodiments, the logic key is created by decrypting a piece of data using a secret decryption key. Advantages of automatic encryption include that existing circuitry need not be re-implemented or re-built, and that the systems and methods presented are backward compatible with standard manufacturing tools.