Spintronic Physical Unclonable Functions Based on Field-Free Spin-Orbit-Torque Switching

Area of Science:

• Materials Science
• Electrical Engineering
• Computer Science

Background:

• Physical Unclonable Functions (PUFs) are crucial for hardware security, leveraging unique physical variations in devices.
• Current silicon- and memristor-based PUFs face limitations in reliability and scalability.
• Software-based security approaches are often less robust than hardware solutions.

Purpose of the Study:

• To demonstrate highly reliable spintronic Physical Unclonable Functions (PUFs).
• To overcome the limitations of existing PUF technologies.
• To offer a scalable and energy-efficient hardware security solution.

Main Methods:

• Utilized field-free spin-orbit-torque switching in IrMn/CoFeB/Ta/CoFeB structures.
• Manipulated exchange bias directions in the IrMn/CoFeB layers to control magnetic switching polarity.
• Characterized the spintronic PUF's entropy, uniqueness, reconfigurability, and digital output.

Main Results:

• Achieved stochastic switching polarity for perpendicular magnetization, serving as a high-entropy source.
• Demonstrated a zero bit-error-rate under repetitive operations.
• Confirmed robustness against external magnetic fields and scalable device implementation.

Conclusions:

• Spintronic PUFs based on IrMn/CoFeB/Ta/CoFeB structures offer a highly reliable and secure hardware primitive.
• The demonstrated technology provides a scalable, energy-efficient, and robust solution for information security.
• This advancement addresses key limitations in current PUF technologies, paving the way for next-generation hardware security.