2015/03/26 by Mordechai Guri, Matan Monitz, Guri, Mordechai +5 · 2 voices · 2 citations
Computer Science · Engineering · #Physical Unclonable Functions (PUFs) and Hardware Security #Electrostatic Discharge in Electronics #Cryptographic Implementations and Security
paper · pdf · doi:10.48550/arxiv.1503.07919
It has been assumed that the physical separation (air-gap) of computers\nprovides a reliable level of security, such that should two adjacent computers\nbecome compromised, the covert exchange of data between them would be\nimpossible. In this paper, we demonstrate BitWhisper, a method of bridging the\nair-gap between adjacent compromised computers by using their heat emissions\nand built-in thermal sensors to create a covert communication channel. Our\nmethod is unique in two respects: it supports bidirectional communication, and\nit requires no additional dedicated peripheral hardware. We provide\nexperimental results based on implementation of BitWhisper prototype, and\nexamine the channel properties and limitations. Our experiments included\ndifferent layouts, with computers positioned at varying distances from one\nanother, and several sensor types and CPU configurations (e.g., Virtual\nMachines). We also discuss signal modulation and communication protocols,\nshowing how BitWhisper can be used for the exchange of data between two\ncomputers in a close proximity (at distance of 0-40cm) at an effective rate of\n1-8 bits per hour, a rate which makes it possible to infiltrate brief commands\nand exfiltrate small amount of data (e.g., passwords) over the covert channel.\n