WebAssembly Based Portable and Secure Sensor Interface for Internet of Things

TL;DR

This paper presents a WebAssembly-based sensor interface for IoT that enhances security and portability, enabling multi-tenant access with minimal latency and memory overhead on embedded devices.

Contribution

It introduces the first WebAssembly System Interface extension for secure, portable sensor access in IoT, with runtime features for isolation and access control on embedded systems.

Findings

Latency overhead of 6% compared to native execution

Memory footprint increases by 5% with WebAssembly extensions

MQTT-SN interface adds less than 1% latency

Abstract

As the expansion of IoT connectivity continues to provide quality-of-life improvements around the world, they simultaneously introduce increasing privacy and security concerns. The lack of a clear definition in managing shared and protected access to IoT sensors offer channels by which devices can be compromised and sensitive data can be leaked. In recent years, WebAssembly has received considerable attention for its efficient application sandboxing suitable for embedded systems, making it a prime candidate for exploring a secure and portable sensor interface. This paper introduces the first WebAssembly System Interface (WASI) extension offering a secure, portable, and low-footprint sandbox enabling multi-tenant access to sensor data across heterogeneous embedded devices. The runtime extensions provide application memory isolation, ensure appropriate resource privileges by intercepting sensor access, and offer an MQTT-SN interface enabling in-network access control. When targeting the WebAssembly byte-code with the associated runtime extensions implemented atop the Zephyr RTOS, our evaluation of sensor access indicates a latency overhead of 6% with an additional memory footprint of 5% when compared to native execution. As MQTT-SN requests are dominated by network delays, the WASI-SN implementation of MQTT-SN introduces less than 1% additional latency with similar memory footprint.