Very Low Cost Entropy Source Based on Chaotic Dynamics Retrofittable on Networked Devices to Prevent RNG Attacks

摘要

Good quality entropy sources are indispensable in most modern cryptographicprotocols. Unfortunately, many currently deployed networked devices do notinclude them and may be vulnerable to Random Number Generator (RNG) attacks.Since most of these systems allow firmware upgrades and have serialcommunication facilities, the potential for retrofitting them with securehardware-based entropy sources exists. To this aim, very low-cost, robust, easyto deploy solutions are required. Here, a retrofittable, sub 10$ entropy sourcebased on chaotic dynamics is illustrated, capable of a 32 kbit/s rate or moreand offering multiple serial communication options including USB, I2C, SPI orUSART. Operation is based on a loop built around the Analog to DigitalConverter (ADC) hosted on a standard microcontroller.