Acoustic Integrity Codes: Secure Device Pairing Using Short-Range Acoustic Communication

Secure Device Pairing (SDP) relies on an out-of-band channel to authenticate devices. This requires a common hardware interface, which limits the use of existing SDP systems. We propose to use short-range acoustic communication for the initial pairing. Audio hardware is commonly available on existing off-the-shelf devices and can be accessed from user space without requiring firmware or hardware modifications. We improve upon previous approaches by designing Acoustic Integrity Codes (AICs): a modulation scheme that provides message authentication on the acoustic physical layer. We analyze their security and demonstrate that we can defend against signal cancellation attacks by designing signals with low autocorrelation. Our system can detect overshadowing attacks using a ternary decision function with a threshold. In our evaluation of this SDP scheme's security and robustness, we achieve a bit error ratio below 0.1% for a net bit rate of 100 bps with a signal-to-noise ratio (SNR) of 14 dB. Using our open-source proof-of-concept implementation on Android smartphones, we demonstrate pairing between different smartphone models.Comment: 11 pages, 11 figures. Published at ACM WiSec 2020 (13th ACM Conference on Security and Privacy in Wireless and Mobile Networks). Updated reference

KALwEN: a new practical and interoperable key management scheme for body sensor networks

Key management is the pillar of a security architecture. Body sensor networks (BSNs) pose several challenges–some inherited from wireless sensor networks (WSNs), some unique to themselves–that require a new key management scheme to be tailor-made. The challenge is taken on, and the result is KALwEN, a new parameterized key management scheme that combines the best-suited cryptographic techniques in a seamless framework. KALwEN is user-friendly in the sense that it requires no expert knowledge of a user, and instead only requires a user to follow a simple set of instructions when bootstrapping or extending a network. One of KALwEN's key features is that it allows sensor devices from different manufacturers, which expectedly do not have any pre-shared secret, to establish secure communications with each other. KALwEN is decentralized, such that it does not rely on the availability of a local processing unit (LPU). KALwEN supports secure global broadcast, local broadcast, and local (neighbor-to-neighbor) unicast, while preserving past key secrecy and future key secrecy (FKS). The fact that the cryptographic protocols of KALwEN have been formally verified also makes a convincing case. With both formal verification and experimental evaluation, our results should appeal to theorists and practitioners alike

Enhancements to Secure Bootstrapping of Smart Appliances

In recent times, there has been a proliferation of smart IoT devices that make our everyday life more convenient, both at home and at work environment. Most of these smart devices are connected to cloud-based online services, and they typically reuse the existing Wi-Fi network infrastructure for Internet connectivity. Hence, it is of paramount importance to ensure that these devices establish a robust security association with the Wi-Fi networks and cloud-based servers. The initial process by which a device establishes a robust security association with the network and servers is known as secure bootstrapping. The bootstrapping process results in the derivation of security keys and other connection parameters required by the security associations. Since the smart IoT devices often possess minimal user-interface, there is a need for bootstrapping methods with which the users can effortlessly connect their smart IoT devices to the networks and services. Nimble out-of-band authentication for Extensible Authentication Protocol (EAP-NOOB) is one such secure bootstrapping method. It is a new EAP authentication method for IEEE 802.1X/EAP authentication framework. The protocol does not assume or require any pre-configured authentication credentials such as symmetric keys or certificates. In lieu, the authentication credentials along with the user’s ownership of the device are established during the bootstrapping process. The primary goal of this thesis is to study and implement the draft specification of the EAP-NOOB protocol in order to evaluate the working of EAP-NOOB in real-world scenarios. During our implementation and testing of the initial prototype for EAP-NOOB, we discovered several issues in the protocol. In this thesis, we propose a suitable solution for each of the problems identified and also, verify the solutions through implementation and testing. The main results of this thesis work are various enhancements and clarifications to the EAP-NOOB protocol specification. The results consequently aid the standardisation of the protocol at IETF. We also design and implement several additional features for EAP-NOOB to enhance the user experience

Secure Device Bootstrapping with the Nimble Out of Band Authentication Protocol

The smart personal and business appliances which form the Internet of Things are expected to become ubiquitous and to make our daily life more convenient. Most of these devices are connected though wireless networks to cloud-based online services. However, such devices may be vulnerable to various attacks which could compromise the users’ security and privacy and even cause physical harm. Therefore, securing the network connection for the devices is of utmost importance. In order to secure the network connections, the devices need to be configured with the necessary keys and other connection parameters. There is not yet any widely adopted generic solution for this secure bootstrapping. One proposed solution is out-of-band (OOB) authentication with a protocol called EAP-NOOB, which is a new method for the EAP and IEEE 802.1X authentication framework. The goal of this thesis is to build a prototype of the EAP-NOOB protocol and deploy the prototype to test it with the real-world scenarios. The protocol requires no a-priori information either about the device or the user is necessary for the bootstrapping. Instead, the user’s ownership of the device is established during the bootstrapping process. The protocol was implemented both by adding support for the new EAP method into existing open-source software, the commonly used WPA_Supplicant and Hostapd packages. We also implemented a web interface for the back-end authentication server, which works in tandem with the AAA server, and out-of-band channels based on dynamic QR codes and NFC tags. We used the prototype to test and demonstrate the EAP-NOOB protocol, including its usability and authentication latency. The bootstrapping procedure can be completed in less than a minute in most cases. The main results of the project are the EAP-NOOB implementation and various improvements and clarifications to the protocol specification. These results are an essential part of the protocol standardization process at IETF

KALwEN: A New Practical and Interoperable Key Management Scheme for Body Sensor Networks

Key management is the pillar of a security architecture. Body sensor networks(BSNs) pose several challenges -- some inherited from wireless sensor networks(WSNs), some unique to themselves -- that require a new key management scheme to be tailor-made. The challenge is taken on, and the result is KALwEN, a new lightweight scheme that combines the best-suited cryptographic techniques in a seamless framework. KALwEN is user-friendly in the sense that it requires no expert knowledge of a user, and instead only requires a user to follow a simple set of instructions when bootstrapping or extending a network. One of KALwEN's key features is that it allows sensor devices from different manufacturers, which expectedly do not have any pre-shared secret, to establish secure communications with each other. KALwEN is decentralized, such that it does not rely on the availability of a local processing unit (LPU). KALwEN supports global broadcast, local broadcast and neighbor-to-neighbor unicast, while preserving past key secrecry and future key secrecy. The fact that the cryptographic protocols of KALwEN have been formally verified also makes a convincing case

Efficient and scalable IPv6 communication functions for wireless outdour lighting networks

Outdoor lighting today is becoming increasingly network-connected. The rapid development in wireless communication technologies makes this progress faster and competitive. Philips Research and Philips Lighting are part of the leading forces in exploration and development of a wide spectrum of low-maintenance, high-quality outdoor/indoor lighting systems that are state of the art. City Touch is a proprietary outdoor lighting connectivity system of Philips Lighting, which is based on a client-server architecture. In an outdoor lighting context, an embedded computer (Node) is installed on a light pole and is connected to different sensors to provide connectivity for the luminaires. Thus, connectivity of luminaires generally refers to the computer network of Nodes. In this report, I present a survey of mechanisms, protocols and technologies that are needed for bootstrapping of wireless Nodes to an IPv6 based personal area network (PAN). The survey indicates that there is no single off-the-shelf product or standard that meets all the requirements of Philips research for its future solution. Hence, I designed a thorough bootstrapping protocol that is custom tailored to Philips 's POLAR architecture. The design brings a solution from pre-deployment configuration to the point where a new Node successfully becomes a part of a wireless network. The design is partially demonstrated with two software implementations. Finally I provide recommendations for future work based on my research

A comprehensive survey of wireless body area networks on PHY, MAC, and network layers solutions

Recent advances in microelectronics and integrated circuits, system-on-chip design, wireless communication and intelligent low-power sensors have allowed the realization of a Wireless Body Area Network (WBAN). A WBAN is a collection of low-power, miniaturized, invasive/non-invasive lightweight wireless sensor nodes that monitor the human body functions and the surrounding environment. In addition, it supports a number of innovative and interesting applications such as ubiquitous healthcare, entertainment, interactive gaming, and military applications. In this paper, the fundamental mechanisms of WBAN including architecture and topology, wireless implant communication, low-power Medium Access Control (MAC) and routing protocols are reviewed. A comprehensive study of the proposed technologies for WBAN at Physical (PHY), MAC, and Network layers is presented and many useful solutions are discussed for each layer. Finally, numerous WBAN applications are highlighted

Kaistan ulkopuolisten todennuskanavien arviointi

One of the challenges in entirely wireless communication systems is authentication. In pervasive computing and peer-to-peer networks, it is often not possible to rely on the existence of a trusted third party or other infrastructure. Therefore, ad hoc verification of keys via an out-of-band (OOB) channel is often the only way to achieve authentication. Nimble out-of-band for EAP (EAP-NOOB) protocol is intended for bootstrapping security between IoT devices with no provisioned authentication credentials and minimal user interface. The protocol supports a user-assisted OOB channel to mutually authenticate the key-exchange performed over an insecure wireless network between the peer and the server. The protocol allows peers to scan for available networks and, based on the results, generate multiple dynamic OOB messages. The user then delivers one of these messages to the server to register the device and authenticate the key-exchange. We implemented the OOB channels using NFC, QR codes and sound with EAP-NOOB as the bootstrapping protocol. The implementation requires an auxiliary device such as the user's smartphone. We evaluated the usability and security as well as the benefits and limitations of the OOB channels. Our results show that NFC and QR codes are capable in displaying multiple OOB messages while the sound-based channel is suitable for one or two messages due to its lower bandwidth. When the peer device generates multiple OOB messages, the process becomes more complex for the user who needs to browse through them and identify the correct server. However, we showed that this cumbersome step can be removed with the help of a mobile application. Furthermore, we identified vulnerabilities in each technology when used as an OOB channel. While some of these vulnerabilities can be mitigated with the mobile application, some require more refined solutions.Yksi täysin langattomien järjestelmien haasteista on todennus. Sulautetussa tietotekniikassa sekä vertaisverkkoissa ei usein voida luottaa maailmanlaajuisesti luotettavan kolmannen osapuolen olemassaoloon. Siksi salausavainten ad hoc-varmennus erillistä tiedonsiirtokanavaa (OOB) käyttäen on usein ainoa ratkaisu turvallisen kommunikaation käynnistämiseksi. Se luo resilienssiä eri hyökkäyksiä vastaan tuomalla järjestelmään toisen, itsenäisen tiedonsiirtokanavan. EAP-NOOB protokolla on tarkoitettu IoT-laitteille, joilla on minimaalinen käyttöliittymä eikä esiasennettuja avaimia. EAP-NOOB tukee käyttäjäavustettua OOB-tiedonsiirtokanavaa, jota käytetään todentamaan suojaamattomassa verkossa suoritettu laitteen ja palvelimen keskinäinen salausavainten vaihto. Protokolla sallii laitteiden kartoittaa käytettävissä olevia verkkoja ja tuottaa sen perusteella dynaamisia todennusviestejä, jotka käyttäjä toimittaa palvelimelle laitteen rekisteröimiseksi. Tässä työssä tutkittiin EAP-NOOB protokollan OOB kanavaa käyttäen NFC:tä, QR-koodeja ja ääntä. Todennusviestin lukeminen laitteelta vaatii käyttäjältä älypuhelimen. Työssä arvioitiin toteutettujen todennuskanavien käytettävyyttä, tietoturvaa, hyötyjä sekä näitä rajoittavia tekijöitä. Työn tulokset osoittavat, että NFC ja QR-koodit soveltuvat näyttämään useita OOB-viestejä. Sen sijaan äänipohjainen kanava soveltuu vain yhdelle tai kahdelle viestille hitaamman tiedonsiirron johdosta. Kun IoT-laite tuottaa useita OOB-viestejä, käyttäjäkokemus muuttuu monimutkaisemmaksi, koska käyttäjän on tunnistettava oikea viesti ja palvelin. Työssä osoitetaan, että tämä käyttäjälle hankala vaihe voidaan välttää erillisellä mobiilisovelluksella. Lisäksi työssä tunnistettiin toteutettujen tiedonsiirtomenetelmien haavoittuvuuksia, kun niitä käytettiin OOB-kanavana. Vaikka osa näistä haavoittuvuuksista voidaan eliminoida mobiilisovelluksen avulla, jotkut niistä vaativat tehokkaampia ratkaisuja