This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Glossy is a flooding-based communication primitive for low-power wireless networks that leverages... more Glossy is a flooding-based communication primitive for low-power wireless networks that leverages constructive interference to achieve high reliability. The Low-power Wireless Bus (LWB) uses Glossy to abstract an entire wireless network into a shared bus like topology. As Glossy is not designed as a secure communication protocol, Glossy and hence LWB are vulnerable to unauthorised eavesdropping and packet injection attacks. In this paper, we propose several security mechanisms to protect Glossy and LWB communication and evaluate their effectiveness in real-world settings. The evaluation of the proposed security mechanisms shows that we can confine the effect of the packet injection attacks on Glossy networks into single hop nodes from the attacker.
With the advent of 6LoWPAN [1], wireless sensor networks (WSN) can be connected to the traditiona... more With the advent of 6LoWPAN [1], wireless sensor networks (WSN) can be connected to the traditional Internet using the well tested IP protocol. These protocols form the Internet of Things (IoT) or strictly speaking the IP-connected IoT. There is no doubt that the 6LoWPAN ...
To bring Internet-grade security to billions of IoT devices and make them first-class Internet ci... more To bring Internet-grade security to billions of IoT devices and make them first-class Internet citizens, IoT devices must move away from pre-shared keys to digital certificates. Public Key Infrastructure, PKI, the digital certificate management solution on the Internet, is inevitable to bring certificate-based security to IoT. Recent research efforts has shown the feasibility of PKI for IoT using Internet security protocols. New and proposed standards enable IoT devices to implement more lightweight solutions for application layer security, offering real end-to-end security also in the presence of proxies.In this paper we present LICE, an application layer enrollment protocol for IoT, an important missing piece before certificate-based security can be used with new IoT standards such as OSCORE and EDHOC. Using LICE, enrollment operations can complete by consuming less than 800 bytes of data, less than a third of the corresponding operations using state-of-art EST-coaps over DTLS. To show the feasibility of our solution, we implement and evaluate the protocol on real IoT hardware in a lossy low-power radio network environment.
IEEE Transactions on Network and Service Management, Dec 1, 2022
Securing IoT devices is gaining attention as the security risks associated with these devices inc... more Securing IoT devices is gaining attention as the security risks associated with these devices increase rapidly. TrustZone-M, a Trusted Execution Environment (TEE) for Cortex-M processors, ensures stronger security within an IoT device by allowing isolated execution of security-critical operations, without trusting the entire software stack. However, TrustZone-M does not guarantee secure cross-world communication between applications in the Normal and Secure worlds. The cryptographic protection of the communication channel is an obvious solution; however, within a low-power IoT device, it incurs high overhead if applied to each cross-world message exchange. We present ShieLD, a framework that enables a secure communication channel between the two TrustZone-M worlds by leveraging the Memory Protection Unit (MPU). ShieLD guarantees confidentiality, integrity and authentication services without requiring any cryptographic operations. We implement and evaluate ShieLD using a Musca-A test chip board with Cortex-M33 that supports TrustZone-M. Our empirical evaluation shows, among other gains, the cross-zone communication protected with ShieLD is 5 times faster than the conventional crypto-based communication.
IoT deployments grow in numbers and size and questions of long time support and maintainability b... more IoT deployments grow in numbers and size and questions of long time support and maintainability become increasingly important. To prevent vendor lock-in, standard compliant capabilities to transfer control of IoT devices between service providers must be offered. We propose a lightweight protocol for transfer of control, and we show that the overhead for the involved IoT devices is small and the overall required manual overhead is minimal. We analyse the fulfilment of the security requirements to verify that the stipulated requirements are satisfied.
Many IoT use cases demand both secure storage and secure communication. Resource-constrained devi... more Many IoT use cases demand both secure storage and secure communication. Resource-constrained devices cannot afford having one set of crypto protocols for storage and another for communication. Lightweight application layer security standards are being developed for IoT communication. Extending these protocols for secure storage can significantly reduce communication latency and local processing. We present BLEND, combining secure storage and communication by storing IoT data as pre-computed encrypted network packets. Unlike local methods, BLEND not only eliminates separate crypto for secure storage needs, but also eliminates a need for real-time crypto operations, reducing the communication latency significantly. Our evaluation shows that compared with a local solution, BLEND reduces send latency from 630 µs to 110 µs per packet. BLEND enables PKI based key management while being sufficiently lightweight for IoT. BLEND doesn't need modifications to communication standards used when extended for secure storage, and can therefore preserve underlying protocols' security guarantees.
This document specifies public key certificate enrollment procedures authenticated with applicati... more This document specifies public key certificate enrollment procedures authenticated with application-layer security protocols suitable for Internet of Things deployments. The protocols leverage existing IoT standards including Constrained Application Protocol (CoAP), Concise Binary Object Representation (CBOR) and the CBOR Object Signing and Encryption (COSE) format.
International Conference on Embedded Wireless Systems and Networks, Feb 9, 2015
Security has arisen as an important issue for the Internet of Things (IoT). Efficient ways to pro... more Security has arisen as an important issue for the Internet of Things (IoT). Efficient ways to provide secure communication between devices and sensors is crucial for the IoT devices, which are beco ...
The WirelessHART is a new standard for Industrial Process Automation and Control, formally releas... more The WirelessHART is a new standard for Industrial Process Automation and Control, formally released in September 2007. WirelessHART specifications are very well organized in all aspects except security as there are no separate specifications that document security requirements, the security is limited and spread throughout the WirelessHART specifications, and it is hard to understand the employed security without reading all the core specifications. This report will provide a comprehensive overview of WirelessHART security, the provided security mechanisms will be analyzed against the possible threats and the solutions will be proposed for the identified shortcomings. The report work also comprises of the ways to integrate the WirelessHART network with the legacy HART network. Different integration options are provided and each differs with the kind of legacy HART network already in use. A secure way of integrating HART and WirelessHART is also proposed by enhancing the capabilities of Adapters and connecting them with the HART Masters rather than slave devices. Finally the architecture of such a Security Manager will be proposed which will be capable of securing the entire WirelessHART network. A comprehensive and secure key management system is proposed which is capable of random key generation, secure key storage and retrieval, secure and automatic key renewal, timely key revocation, and efficient key distribution.
ACM Transactions in Embedded Computing Systems, Apr 28, 2017
This article presents Axiom, a DTLS-based approach to efficiently secure multicast group communic... more This article presents Axiom, a DTLS-based approach to efficiently secure multicast group communication among IoT constrained devices. Axiom provides an adaptation of the DTLS record layer, relies on key material commonly shared among the group members, and does not require to perform any DTLS handshake. We made a proof of concept implementation of Axiom based on the tinyDTLS library for the Contiki OS, and used it to experimentally evaluate performance of our approach on real IoT hardware. Results show that Axiom is affordable on resource constrained platforms, and performs significantly better than related alternative approaches.
HAL (Le Centre pour la Communication Scientifique Directe), Nov 2, 2020
This document specifies public-key certificate enrollment procedures protected with lightweight a... more This document specifies public-key certificate enrollment procedures protected with lightweight application-layer security protocols suitable for Internet of Things (IoT) deployments. The protocols leverage payload formats defined in Enrollment over Secure Transport (EST) and existing IoT standards including the Constrained Application Protocol (CoAP), Concise Binary Object Representation (CBOR) and the CBOR Object Signing and Encryption (COSE) format. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts.
The Internet of Things (IoT) is the interconnection of everyday physical objects with the Interne... more The Internet of Things (IoT) is the interconnection of everyday physical objects with the Internet and their representation in the digital world. Due to the connectivity of physical objects with the untrusted Internet, security has become an important pillar for the success of IoT-based services. Things in the IoT are resource-constrained devices with limited processing and storage capabilities. Often, these things are battery powered and connected through lossy wireless links. Therefore, lightweight and efficient ways of providing secure communication in the IoT are needed. In this context, Elliptic Curve Cryptography (ECC) is considered as a strong candidate to provide security in the IoT while being able to function in constrained environments. In this paper we present a lightweight implementation and evaluation of ECC for the Contiki OS. For fast, secure and cost-effective mass development of IoT-based services by different vendors, it is important that the IoT protocols are implemented and released as open source and open licensed. To the best of our knowledge our ECC is the first lightweight BSD-licensed ECC for the IoT devices. We show the feasibility of our implementation by a thorough performance analysis using several implementations and optimization algorithms. Moreover, we evaluate it on a real IoT hardware platform.
The increase of the computational power in edge devices has enabled the penetration of distribute... more The increase of the computational power in edge devices has enabled the penetration of distributed machine learning technologies such as federated learning, which allows to build collaborative models performing the training locally in the edge devices, improving the efficiency and the privacy for training of machine learning models, as the data remains in the edge devices. However, in some IoT networks the connectivity between devices and system components can be limited, which prevents the use of federated learning, as it requires a central node to orchestrate the training of the model. To sidestep this, peer-to-peer learning appears as a promising solution, as it does not require such an orchestrator. On the other side, the security challenges in IoT deployments have fostered the use of machine learning for attack and anomaly detection. In these problems, under supervised learning approaches, the training datasets are typically imbalanced, i.e. the number of anomalies is very small compared to the number of benign data points, which requires the use of re-balancing techniques to improve the algorithms' performance. In this paper, we propose a novel peer-to-peer algorithm,P2PK-SMOTE, to train supervised anomaly detection machine learning models in non-IID scenarios, including mechanisms to locally re-balance the training datasets via synthetic generation of data points from the minority class. To improve the performance in non-IID scenarios, we also include a mechanism for sharing a small fraction of synthetic data from the minority class across devices, aiming to reduce the risk of data de-identification. Our experimental evaluation in real datasets for IoT anomaly detection across a different set of scenarios validates the benefits of our proposed approach. CCS CONCEPTS • Security and privacy → Mobile and wireless security; Intrusion/anomaly detection and malware mitigation; • Computing methodologies → Machine learning.
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Glossy is a flooding-based communication primitive for low-power wireless networks that leverages... more Glossy is a flooding-based communication primitive for low-power wireless networks that leverages constructive interference to achieve high reliability. The Low-power Wireless Bus (LWB) uses Glossy to abstract an entire wireless network into a shared bus like topology. As Glossy is not designed as a secure communication protocol, Glossy and hence LWB are vulnerable to unauthorised eavesdropping and packet injection attacks. In this paper, we propose several security mechanisms to protect Glossy and LWB communication and evaluate their effectiveness in real-world settings. The evaluation of the proposed security mechanisms shows that we can confine the effect of the packet injection attacks on Glossy networks into single hop nodes from the attacker.
With the advent of 6LoWPAN [1], wireless sensor networks (WSN) can be connected to the traditiona... more With the advent of 6LoWPAN [1], wireless sensor networks (WSN) can be connected to the traditional Internet using the well tested IP protocol. These protocols form the Internet of Things (IoT) or strictly speaking the IP-connected IoT. There is no doubt that the 6LoWPAN ...
To bring Internet-grade security to billions of IoT devices and make them first-class Internet ci... more To bring Internet-grade security to billions of IoT devices and make them first-class Internet citizens, IoT devices must move away from pre-shared keys to digital certificates. Public Key Infrastructure, PKI, the digital certificate management solution on the Internet, is inevitable to bring certificate-based security to IoT. Recent research efforts has shown the feasibility of PKI for IoT using Internet security protocols. New and proposed standards enable IoT devices to implement more lightweight solutions for application layer security, offering real end-to-end security also in the presence of proxies.In this paper we present LICE, an application layer enrollment protocol for IoT, an important missing piece before certificate-based security can be used with new IoT standards such as OSCORE and EDHOC. Using LICE, enrollment operations can complete by consuming less than 800 bytes of data, less than a third of the corresponding operations using state-of-art EST-coaps over DTLS. To show the feasibility of our solution, we implement and evaluate the protocol on real IoT hardware in a lossy low-power radio network environment.
IEEE Transactions on Network and Service Management, Dec 1, 2022
Securing IoT devices is gaining attention as the security risks associated with these devices inc... more Securing IoT devices is gaining attention as the security risks associated with these devices increase rapidly. TrustZone-M, a Trusted Execution Environment (TEE) for Cortex-M processors, ensures stronger security within an IoT device by allowing isolated execution of security-critical operations, without trusting the entire software stack. However, TrustZone-M does not guarantee secure cross-world communication between applications in the Normal and Secure worlds. The cryptographic protection of the communication channel is an obvious solution; however, within a low-power IoT device, it incurs high overhead if applied to each cross-world message exchange. We present ShieLD, a framework that enables a secure communication channel between the two TrustZone-M worlds by leveraging the Memory Protection Unit (MPU). ShieLD guarantees confidentiality, integrity and authentication services without requiring any cryptographic operations. We implement and evaluate ShieLD using a Musca-A test chip board with Cortex-M33 that supports TrustZone-M. Our empirical evaluation shows, among other gains, the cross-zone communication protected with ShieLD is 5 times faster than the conventional crypto-based communication.
IoT deployments grow in numbers and size and questions of long time support and maintainability b... more IoT deployments grow in numbers and size and questions of long time support and maintainability become increasingly important. To prevent vendor lock-in, standard compliant capabilities to transfer control of IoT devices between service providers must be offered. We propose a lightweight protocol for transfer of control, and we show that the overhead for the involved IoT devices is small and the overall required manual overhead is minimal. We analyse the fulfilment of the security requirements to verify that the stipulated requirements are satisfied.
Many IoT use cases demand both secure storage and secure communication. Resource-constrained devi... more Many IoT use cases demand both secure storage and secure communication. Resource-constrained devices cannot afford having one set of crypto protocols for storage and another for communication. Lightweight application layer security standards are being developed for IoT communication. Extending these protocols for secure storage can significantly reduce communication latency and local processing. We present BLEND, combining secure storage and communication by storing IoT data as pre-computed encrypted network packets. Unlike local methods, BLEND not only eliminates separate crypto for secure storage needs, but also eliminates a need for real-time crypto operations, reducing the communication latency significantly. Our evaluation shows that compared with a local solution, BLEND reduces send latency from 630 µs to 110 µs per packet. BLEND enables PKI based key management while being sufficiently lightweight for IoT. BLEND doesn't need modifications to communication standards used when extended for secure storage, and can therefore preserve underlying protocols' security guarantees.
This document specifies public key certificate enrollment procedures authenticated with applicati... more This document specifies public key certificate enrollment procedures authenticated with application-layer security protocols suitable for Internet of Things deployments. The protocols leverage existing IoT standards including Constrained Application Protocol (CoAP), Concise Binary Object Representation (CBOR) and the CBOR Object Signing and Encryption (COSE) format.
International Conference on Embedded Wireless Systems and Networks, Feb 9, 2015
Security has arisen as an important issue for the Internet of Things (IoT). Efficient ways to pro... more Security has arisen as an important issue for the Internet of Things (IoT). Efficient ways to provide secure communication between devices and sensors is crucial for the IoT devices, which are beco ...
The WirelessHART is a new standard for Industrial Process Automation and Control, formally releas... more The WirelessHART is a new standard for Industrial Process Automation and Control, formally released in September 2007. WirelessHART specifications are very well organized in all aspects except security as there are no separate specifications that document security requirements, the security is limited and spread throughout the WirelessHART specifications, and it is hard to understand the employed security without reading all the core specifications. This report will provide a comprehensive overview of WirelessHART security, the provided security mechanisms will be analyzed against the possible threats and the solutions will be proposed for the identified shortcomings. The report work also comprises of the ways to integrate the WirelessHART network with the legacy HART network. Different integration options are provided and each differs with the kind of legacy HART network already in use. A secure way of integrating HART and WirelessHART is also proposed by enhancing the capabilities of Adapters and connecting them with the HART Masters rather than slave devices. Finally the architecture of such a Security Manager will be proposed which will be capable of securing the entire WirelessHART network. A comprehensive and secure key management system is proposed which is capable of random key generation, secure key storage and retrieval, secure and automatic key renewal, timely key revocation, and efficient key distribution.
ACM Transactions in Embedded Computing Systems, Apr 28, 2017
This article presents Axiom, a DTLS-based approach to efficiently secure multicast group communic... more This article presents Axiom, a DTLS-based approach to efficiently secure multicast group communication among IoT constrained devices. Axiom provides an adaptation of the DTLS record layer, relies on key material commonly shared among the group members, and does not require to perform any DTLS handshake. We made a proof of concept implementation of Axiom based on the tinyDTLS library for the Contiki OS, and used it to experimentally evaluate performance of our approach on real IoT hardware. Results show that Axiom is affordable on resource constrained platforms, and performs significantly better than related alternative approaches.
HAL (Le Centre pour la Communication Scientifique Directe), Nov 2, 2020
This document specifies public-key certificate enrollment procedures protected with lightweight a... more This document specifies public-key certificate enrollment procedures protected with lightweight application-layer security protocols suitable for Internet of Things (IoT) deployments. The protocols leverage payload formats defined in Enrollment over Secure Transport (EST) and existing IoT standards including the Constrained Application Protocol (CoAP), Concise Binary Object Representation (CBOR) and the CBOR Object Signing and Encryption (COSE) format. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts.
The Internet of Things (IoT) is the interconnection of everyday physical objects with the Interne... more The Internet of Things (IoT) is the interconnection of everyday physical objects with the Internet and their representation in the digital world. Due to the connectivity of physical objects with the untrusted Internet, security has become an important pillar for the success of IoT-based services. Things in the IoT are resource-constrained devices with limited processing and storage capabilities. Often, these things are battery powered and connected through lossy wireless links. Therefore, lightweight and efficient ways of providing secure communication in the IoT are needed. In this context, Elliptic Curve Cryptography (ECC) is considered as a strong candidate to provide security in the IoT while being able to function in constrained environments. In this paper we present a lightweight implementation and evaluation of ECC for the Contiki OS. For fast, secure and cost-effective mass development of IoT-based services by different vendors, it is important that the IoT protocols are implemented and released as open source and open licensed. To the best of our knowledge our ECC is the first lightweight BSD-licensed ECC for the IoT devices. We show the feasibility of our implementation by a thorough performance analysis using several implementations and optimization algorithms. Moreover, we evaluate it on a real IoT hardware platform.
The increase of the computational power in edge devices has enabled the penetration of distribute... more The increase of the computational power in edge devices has enabled the penetration of distributed machine learning technologies such as federated learning, which allows to build collaborative models performing the training locally in the edge devices, improving the efficiency and the privacy for training of machine learning models, as the data remains in the edge devices. However, in some IoT networks the connectivity between devices and system components can be limited, which prevents the use of federated learning, as it requires a central node to orchestrate the training of the model. To sidestep this, peer-to-peer learning appears as a promising solution, as it does not require such an orchestrator. On the other side, the security challenges in IoT deployments have fostered the use of machine learning for attack and anomaly detection. In these problems, under supervised learning approaches, the training datasets are typically imbalanced, i.e. the number of anomalies is very small compared to the number of benign data points, which requires the use of re-balancing techniques to improve the algorithms' performance. In this paper, we propose a novel peer-to-peer algorithm,P2PK-SMOTE, to train supervised anomaly detection machine learning models in non-IID scenarios, including mechanisms to locally re-balance the training datasets via synthetic generation of data points from the minority class. To improve the performance in non-IID scenarios, we also include a mechanism for sharing a small fraction of synthetic data from the minority class across devices, aiming to reduce the risk of data de-identification. Our experimental evaluation in real datasets for IoT anomaly detection across a different set of scenarios validates the benefits of our proposed approach. CCS CONCEPTS • Security and privacy → Mobile and wireless security; Intrusion/anomaly detection and malware mitigation; • Computing methodologies → Machine learning.
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