SPoTKD: A Protocol for Symmetric Key Distribution over Public Channels Using Self-Powered Timekeeping Devices

TL;DR

This paper introduces SPoTKD, a novel symmetric key distribution protocol utilizing synchronized self-powered timers in low-cost hardware, providing secure, tamper-resistant keys derived from physical timer dynamics for communication between users and servers.

Contribution

The paper presents a new key distribution protocol based on physical timer behavior, demonstrating its security, randomness, and robustness through simulations and error correction methods.

Findings

Keys derived from timers pass NIST randomness tests.

Protocols are secure against standard and adversarial attacks.

Error correction enhances robustness in real-world conditions.

Abstract

In this paper, we propose a novel class of symmetric key distribution protocols that leverages basic security primitives offered by low-cost, hardware chipsets containing millions of synchronized self-powered timers. The keys are derived from the temporal dynamics of a physical, micro-scale time-keeping device which makes the keys immune to any potential side-channel attacks, malicious tampering, or snooping. Using the behavioral model of the self-powered timers, we first show that the derived key-strings can pass the randomness test as defined by the National Institute of Standards and Technology (NIST) suite. The key-strings are then used in two SPoTKD (Self-Powered Timer Key Distribution) protocols that exploit the timer's dynamics as one-way functions: (a) protocol 1 facilitates secure communications between a user and a remote Server, and (b) protocol 2 facilitates secure communications between two users. In this paper, we investigate the security of these protocols under standard model and against different adversarial attacks. Using Monte-Carlo simulations, we also investigate the robustness of these protocols in the presence of real-world operating conditions and propose error-correcting SPoTKD protocols to mitigate these noise-related artifacts.