Magnetic tactile sensors can be hacked with hidden magnetic tags
PhantomTac: Hijacking Robotic Tactile Systems with Deploy-and-forget Tags
Cryptography and SecurityRobotics
Summary
Robotic hands use magnetic touch sensors to feel how hard they grip objects. This study found that attackers can secretly attach tiny magnetic tags to objects, tricking the robot into misreading the forces. Because of this, robots might squeeze too hard and break things or hold too loosely and drop them. The researchers tested these attacks on real robots and showed they work often, then suggested a way to defend against them.
What this means in practice
- •For robotic system integrators: Design safer robotic grasping setups by accounting for magnetic tag spoofing threats to tactile sensors in manufacturing and logistics automation.
- •For robot security teams: Defend industrial robots from hidden magnetic attacks by implementing cross-sensor consistency checks to detect spoofed tactile signals.
Authors
Binbin Zhang, Yifeng Zhang, Xiaomeng Chen, Dongyao Chen
Abstract
Tactile perception is crucial for precise robotic manipulation, providing an important foundation for dexterous, closed-loop force control. Among various tactile sensing techniques, magnetic tactile sensors stand out thanks to their fine-grained, three-dimensional force perception capability and strong robustness against visual occlusion. In this study, we discover a physical loophole called PhantomTac in magnetic tactile sensors. The attacker can alter the magnetic field, thus spoofing the force interpreted by magnetic tactile sensors. The attacker can stealthily deploy such an attack by simply attaching a thin (the thickness is around 0.5 mm), battery-free magnetic tag to the surface of an object. Hence, the attack tag can be easily concealed by a barcode sticker. Such an attack scheme is "deploy-and-forget" -- the attacker can deploy the tag and leave. When a robotic hand is picking up an object, it may severely damage the object. Specifically, spoofing the normal force can crush the object, whereas spoofing the shear force can lead to a loose grip, thus dropping the object. Compared with directly sabotaging the robotic hand, PhantomTac is much more concealed as the attacker does not need access to the device. We performed extensive reverse-engineering efforts to characterize the sensing mechanism of commercial-off-the-shelf tactile sensors and proposed a practical tag design. End-to-end evaluations conducted on real robots and robotic arms demonstrate that our attack can bypass existing anti-interference mechanisms and effectively hijack their closed-loop control processes, achieving an attack success rate exceeding 95% when the grasping-position offset is bounded within 8 mm. Finally, based on the limitations of existing anti-magnetic interference mechanisms, we propose a multimodal-consistency defense mechanism to mitigate such physical-layer security threats.