Logic Gate Encryption Using PUF Keys Against Reverse Engineering
Find Innovative SolutionsGenerate Solutions
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, leading to exposure and unauthorized distribution of devices.
Innovation Solution
Implementing logic key encryption by using encrypted logic keys stored in tamperproof storage, which determine the physical wiring of logic building blocks, and employing generic logic blocks that require a valid logic key to function correctly, along with secure physical elements like Physically Unclonable Functions (PUFs) for enhanced security.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional encryption methods are used in hardware, then security against reverse engineering is improved, but the complexity of the system increases and manufacturing becomes more difficult
Solution Approach 1:
The patent extracts the encryption key from the logic function itself by separating the key generation process from the logic implementation. Generic logic blocks are used to implement the logic function, while the encryption key is generated separately using PUFs and stored in secure memory, eliminating the need for complex hardwired encryption circuits within the logic blocks themselves.
Solution Approach 2:
The patent introduces PUFs (Physically Unclonable Functions) as an intermediary mechanism to generate encryption keys. The PUFs serve as a secure key generation layer that mediates between the hardware implementation and the encryption requirement, providing security without requiring complex encryption logic to be embedded in the generic logic blocks.
2Reliability
If encryption keys are embedded in hardware logic gates, then security is improved, but reverse engineering can still easily access and exploit these keys
Solution Approach 1:
The encryption key is extracted from the logic function implementation and stored separately in secure memory rather than being hardwired into the logic gates. The generic logic blocks execute the logic function without containing the encryption key, making reverse engineering unable to extract the key from the logic implementation.
Solution Approach 2:
The patent uses PUFs which generate encryption keys based on physical characteristics that are extremely difficult to replicate. The security model accepts that the physical device may be compromised but relies on the unclonability of the PUF to prevent key extraction, effectively treating the physical instance as a disposable secure element.
3Object-affected harmful factors
If generic logic blocks are used instead of specific logic gates, then security against reverse engineering is improved, but the difficulty of detecting and measuring the actual logic function increases
Solution Approach 1:
The patent employs universal generic logic blocks that can implement any logic function through configuration rather than having dedicated hardware for each specific function. This universality provides security because the same physical block can represent different logic functions depending on the configuration, making reverse engineering unable to determine the actual function without the encryption key.
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 or private 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.