Hardware PUF Key Generation for IoT Security

The patent replaces software-based encryption systems with hardware-based Physical Unclonable Functions (PUFs) implemented in semiconductor devices. The PUFs utilize physical characteristics of semiconductor structures (such as variations in transistor threshold voltages or resistor values) to generate cryptographic keys, moving the security function from the software domain to the hardware domain. This substitution makes the system more resistant to software-based attacks while maintaining ease of operation through automated key generation.

The patent creates unclonable physical copies of security credentials embedded in semiconductor devices. Each device contains a unique PUF that generates cryptographic keys based on its specific physical characteristics, which cannot be replicated or copied. This allows multiple devices to have identical functionality while maintaining unique, uncopyable security credentials, enabling secure communication without centralized key management.

The patent merges the PUF functionality with standard semiconductor device structures that already exhibit nonlinear I-V characteristics, such as diodes, transistors, or resistors. Instead of adding separate PUF hardware components, the invention utilizes the inherent physical properties of existing device elements to generate cryptographic keys. This integration approach maintains security reliability while minimizing increases in device complexity.

The patent makes standard semiconductor devices serve dual purposes: their primary function (e.g., switching, rectification, or resistance) and cryptographic key generation through their physical characteristics. The nonlinear I-V characteristics of common semiconductor components are exploited to create PUF functionality, allowing these universal components to provide both circuit operation and security functions simultaneously, thereby reducing overall device complexity.