Physical Layer Security for 6G IoT: Anti-Jamming & Efficiency

Introduction : The Internet of Things (IoT) is the backbone of the 6G vision, promising to connect billions of devices from smart home sensors to industrial actuators. Most of the IoT devices are very compact, low cost and run on tiny batteries with very limited processing power.

Traditional cryprographic security algorithms are too heavy for these devices to incorporate and handle. Moreover managing secret keys for such number of devices is logistical nightmare. Moreover devices consume more power than they are designed for.

While eavesdropping is a concern, Jamming is a particularly devastating threat for IoT networks in the 6G era. In targetted threat, IoT devices are continuously bombard with noise or fake requests which led to battery drain in hours instead of years.

Due to above mentioned reasons, 6G is turning into physical layer security (PLS) instead of complex software algorithms.

Anti-Jamming techniques for IoT devices in 6G

Following are several physical layer security (PLS) strategies that allow low power devices to resist jamming without requiring heavy computation.

1. Intelligent Spread Spectrum: Traditional Frequency Hopping (FHSS) spreads signals across different frequencies to avoid interference. However, standard hopping sequences can be predicted by smart jammers. 6G IoT introduces advanced variations such as probabilistic hopping, encrypted hopping sequences and chirp spread spectrum (CSS). These techniques make it impossible for jammers to achieve their melicious goals to disrupt the communication.

2. Reconfigurable Intelligent Surfaces (RIS) as Shields:

As these passive panels can steer radio waves, they are one of the most promising anti-jamming technologies for 6G IoT.

• If a jammer blocks the direct path between an IoT sensor and the Base Station, an RIS can create an instant “alternative path,” reflecting the signal around the jammer.
• More advanced RIS implementations can reflect a copy of the jamming signal back at the receiver with an inverted phase. This uses “destructive interference” to mathematically cancel out the noise, cleaning the spectrum for the legitimate data.

3. mmWave and Beamforming for IoT: 6G will push IoT devices into higher frequency bands (mmWave and Terahertz). Higher frequencies have tiny wavelengths, meaning even small IoT devices can pack multiple antennas. This enables beamforming. Instead of broadcasting data in all directions (where jammer can easily interfere), the IoT device shoots a laser beam of data to the base station. To jam this, an attacker would have to physically stand directly in the narrow beam path, making jamming significantly harder.

4. Energy Harvesting for Resilience: To counter the “battery drain” caused by jamming, 6G IoT devices will utilize Energy Harvesting. Devices harvest energy from environmental sources (solar, thermal) or even from the radio waves of the jamming signal itself.

Summary:

For 6G IoT, security is no longer just about encryption keys; it is about survival. By leveraging Physical Layer Security, we can protect simple devices from sophisticated attacks. Techniques like Intelligent Spread Spectrum, RIS, and Energy Harvesting ensure that the massive IoT networks of the future remain robust, efficient, and awake only when they need to be.