Multichannel Protocols for User-Friendly and Scalable Initialization of Sensor Networks

Abstract

Abstract. We consider the classical problem of establishing initial security associations in wireless sensor networks. More specifically, we focus on pre-deployment phase in which sensor nodes have not yet been loaded with shared secrets or other forms of authentic information.In this paper, we propose two novel multichannel protocols for initialization of large scale wireless sensor networks. The first protocol uses only secret key cryptography and is suitable for CPU-constrained sensor nodes. The second protocol is based on public key cryptography. Both protocols involve communication over a bidirectional radio channel and an unidirectional out-of-band visible light channel. A notable feature of the proposed "public key"-based key deployment protocol is that it is designed to be secure in a very strong attacker model, where an attacker can eavesdrop, jam and modify transmitted messages by adding his own message to both a radio and a visible light channel; the attacker however cannot disable the visible light communication channel. We show that many existing protocols that rely on the visible light channel are insecure in this strong adversary model.We implemented the proposed protocols on the Meshnetics wireless sensor platform. The proposed protocols are cheap to implement, secure in the very strong attacker model, easy to use and scalable. We also designed and tested a simple random number generator suitable for sensor platforms.

Out-of-Band Covert Channels—A Survey

“…Their algorithm, however, required a human to interact with one of the devices to complete the protocol. Similar LED-based approaches are discussed in [Gauger et al 2009;Perković et al 2009;Roman and Lopez 2008] to perform key assignment in ad-hoc wireless sensors networks.…”

“…This too is a form of "security through obscurity" as any entity monitoring the light intensity in the room would be able to detect that "covert" communication is taking place. Additionally, in [Gauger et al 2009;Perković et al 2009], the researchers made the assumption that no adversary had access to the light-based communication channel. This assumption is not valid in our model, but one that is perhaps valid in the context of initial key assignment and shows that more research is required to determine ways in which light communication can be used to meet the security requirements of out-of-band covert communications.…”

Flashing displays: user-friendly solution for bootstrapping secure associations between multiple constrained wireless devices

“…The main motivation to use I ‐codes for transmission of public messages rather than using approaches in which users verify public messages communicated via VLC is to design a solution that minimizes participation by non‐specialist users.…”

“…In Human‐Assisted Pure Audio Device Pairing (HAPADEP) , both data and verification information are sent over an audio channel, and thus, the pairing devices have to be equipped with speakers and microphones. Saxena and Udin in and Saxena et al in and Perkovic et al in present device pairing methods based on device equipped with LEDs and a video camera as the receiver. In , Perkovic et al propose a solution that allows an unaided user to initialize a relatively large number of wireless devices.…”

“…In this scheme, we use VLC channel in combination with a security primitive integrity codes ( I‐codes) . Unlike similar approaches in , where VLC is used for transmission of short authentication strings, in the present scheme, VLC is used only as a means to synchronize specially crafted ( I ‐coded) radio messages and to easy the process of loading the group size info into interface limited devices. Similar approaches based on I ‐codes appear in (Tamper‐Evident Pairing (TEP) protocol) and in (Chorus protocol).…”