Realizing access control to sensitive data offloaded to a Cloud is challenging in the Internet of Things, where various devices with low computational power and different security levels are interconnected. Despite various solutions, the National Institute of Standards and Technology (NIST)'s Attribute-Based Access Control (ABAC) model is one of the preferred techniques in the literature. In this model, users who satisfy access policies using both static and dynamic attributes are allowed to access the data. However, NIST's ABAC model does not support encryption and therefore does not satisfy data confidentiality. Attribute-Based Encryption (ABE) is a known cryptographic primitive that enables fine-grained access control over encrypted data. However, currently the existing ABE schemes do not meet NIST's ABAC requirements or are not computationally efficient enough for IoT applications. In this paper, we propose a Multi-Level Security ABAC (MLS-ABAC) scheme that satisfies the requirements of NIST's ABAC model. Our construction is efficient and relies on a decryption outsourceable Ciphertext-Policy ABE scheme. Additionally, based on realistic application scenarios, only the authorized data users can decrypt the ciphertext, and check the integrity of the retrieved message. Furthermore, we present both conceptual and formal models for our proposed MLS-ABAC architecture along with performance metrics. The experimental results show that the proposed MLS-ABAC achieves a constant ciphertext size of similar to 230 bytes and with encryption and decryption running times of similar to 18 and similar to 10 ms, respectively, independent of the number of attributes. (c) 2022 The Author(s). Published by Elsevier B.V.This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

P reserving the confidentiality of sensitive Electronic Health Records (EHRs), stored on a medical server, is an essential issue in healthcare systems. The system should have the means to avoid unauthorized users from accessing this sensitive information. This security problem has been tackled in the ProTego project, where an access control mechanism is developed as an integral part of a toolkit for data protection in healthcare. Without the appropriate access control mechanisms, it is impossible to protect the EHRs. This white paper discusses multiple technical approaches to provide access control and key management for healthcare systems.

Designers of smart environments based on radio frequency identification devices have a challenging task to build secure mutual authentication protocols. These systems are classified into two major factions which are traditional closed-loop systems, and open-loop systems. To the best of our knowledge, all of the mutual authentication protocols previously introduced for these two categories rely on a centralized database but they fail to address decentralized mutual authentication and their related attacks. Thanks to the blockchain technology, which is a novel distributed technology, in this paper, we propose two decentralized mutual authentication protocols for IoT systems. Our first scheme is utilized for traditional closed-loop RFID systems (called CLAB), and the second one applies to open-loop RFID systems (called OLAB). Meanwhile, we examine the security of the Chebyshev chaotic map-based authentication algorithm and confirm that this algorithm is unprotected against tag and reader impersonation attacks. Likewise, we present a denial of service (DoS), tag impersonation, and reader impersonation attacks against the Chebyshev chaotic-map based protocol when employed in open-loop IoT networks. Moreover, we discover a full secret recovery attack against a recent RFID mutual authentication protocol which is based on blockchain. Finally, we use the BAN-logic method to approve the security characteristics of our CLAB and OLAB proposals.

Recently, blockchain-based Internet of Medical Things (IoMT) has started to receive more attention in the healthcare domain as it not only improves the care quality using real-time and continuous monitoring but also minimizes the cost of care. However, there is a clear trend to include many entities in IoMT systems, such as IoMT sensor nodes, IoT wearable medical devices, patients, healthcare centers, and insurance companies. This makes it challenging to design a blockchain framework for these systems where scalability is a most critical factor in blockchain technology. Motivated by this observation, in this survey we review the state-of-the-art in blockchain-IoMT systems. Comparison and analysis of such systems prove that there is a substantial gap, which is the negligence of scalability. In this survey, we discuss several approaches proposed in the literature to improve the scalability of blockchain technology, and thus overcoming the above mentioned research gap. These approaches include on-chain and off-chain techniques, based on which we give recommendations and directions to facilitate designing a scalable blockchain-based IoMT system. We also recommended that a designer considers the well-known trilemma along with the various dimensions of a scalable blockchain system to prevent sacrificing security and decentralization as well. Moreover, we raise several research questions regarding benchmarking; addressing these questions could help designers determining the existing bottlenecks, leading to a scalable blockchain.

Design of ultralightweight authentication protocols for RFID systems conformed with the EPC Class-1 Generation-2 standard is still a challenging issue in RFID security. Recently, Maurya et al. proposed a CRC-based authentication protocol and claimed that their protocol resists against all attacks known in RFID systems. However, in this paper, we criticize employment of CRC function as a security primitive for authentication protocols by proposing two serious attacks against Maurya et al.'s protocol. These two effective and low-complexity attacks include a tag impersonation attack and a tag traceability attack. Our attacks use the linearity of the CRC function employed in this protocol. Our analyses show that the success probability of our attacks is "1" while the complexity is only one session eavesdropping, two XORs and one CRC computation. Moreover, we verify correctness of our attacks by simulating them.

. Lightweight authenticated key exchange (AKE) protocols based on symmetric-key cryptography is important in securing the Internet of Things (IoT). However, achieving perfect forward secrecy (PFS) is not trivial for AKE based on symmetric-key cryptography, as opposed to AKE based on public-key cryptography. The most recent proposals that provide PFS are SAKE and SAKE-AM. In this paper, we first take a closer look at these protocols and observe that they are vulnerable to a number of attacks, such as, replay attack, denial of service (DoS) attack, tracking attack, etc. We then pro-pose countermeasures to both protocols to restore security. Additionally, our proposed scheme SAKE + enables concurrent execution of the protocol, whereas the original SAKE scheme supports the sequential execution of the protocol. The concurrency provided by our scheme makes it more suitable for IoT applications where a server receives and sends information from a large number of IoT end devices. Finally, we prove the security and soundness of our schemes, and verify using ProVerif tool.

Nowadays, many people perform their commercial activities, such as electronic payment and electronic banking, through their mobile phones. Mobile commerce (m‐commerce) refers to manipulating electronic commerce (e‐commerce) by using mobile devices and wireless networks. Radio‐frequency identification (RFID) is a technology which can be employed to complete payment functions on m‐commerce. As an RFID subsystem is applied in m‐commerce and supply chains, the related security concerns are very important. Recently, Fan et al. have proposed an ultra‐lightweight RFID authentication scheme for m‐commerce (ULRAS) and claimed that their protocol is efficient enough and provides a high level of security. In this paper, we show that their protocol is vulnerable to secret disclosure and reader impersonation attacks. Finally, we improve it to a protocol that is resistant to the attacks presented in this paper and the other known attacks in the context of RFID authentication. We further analyze the security of the improved protocol through the Burrows–Abadi–Needham logic (BAN‐logic). Moreover, our proposed improvement does not impose any additional workload on the RFID tag.

The use of the Internet of Things (IoT) in the electronic health (e-health) management systems brings with it many challenges, including secure communications through insecure radio channels, authentication and key agreement schemes between the entities involved, access control protocols and also schemes for transferring ownership of vital patient information. Besides, the resource-limited sensors in the IoT have real difficulties in achieving this goal. Motivated by these considerations, in this work we propose a new lightweight authentication and ownership transfer protocol for e-health systems in the context of IoT (LACO in short). The goal is to propose a secure and energy-efficient protocol that not only provides authentication and key agreement but also satisfies access control and preserves the privacy of doctors and patients. Moreover, this is the first time that the ownership transfer of users is considered. In the ownership transfer phase of the proposed scheme, the medical server can change the ownership of patient information. In addition, the LACO protocol overcomes the security flaws of recent authentication protocols that were proposed for e-health systems, but are unfortunately vulnerable to traceability, de-synchronization, denial of service (DoS), and insider attacks. To avoid past mistakes, we present formal (i.e., conducted on ProVerif language) and informal security analysis for the LACO protocol. All this ensures that our proposed scheme is secure against the most common attacks in IoT systems. Compared to the predecessor schemes, the LACO protocol is both more efficient and more secure to use in e-health systems.

Wireless sensor networks (WSNs) play an important role and support a variety of real time applications, such as healthcare monitoring, military surveillance, vehicular tracking and, so on. Secure and real time information accessing from the sensor nodes in these applications is very important. Because wireless sensor nodes are limited in computing and communication capabilities and data storage, it is very crucial to design an effective and secure lightweight authentication and key agreement scheme. Recently, Gope et al. proposed a realistic lightweight anonymous authentication scheme in WSNs and claimed that their scheme satisfied all security concerns in these networks. However, we show that in their scheme the adversary can obtain the session key between the user and the sensor node. In order to fix this drawback, we propose an improved three-factor authentication scheme which is more suitable than Gope et al.’s scheme and also provides more desired security properties such as three-factor authentication and access control. Through the informal analysis, we show that our scheme is secure against various known attacks including the attack found in Gope et al.’s scheme. Furthermore, we have demonstrated the validity of our proposed scheme using the BAN logic. As compared with the previous authentication schemes, the proposed scheme is not only more secure but also enough practical and competitive with existing schemes.

The safety of medical data and equipment plays a vital role in today's world of Medical Internet of Things (MIoT). These IoT devices have many constraints (e.g., memory size, processing capacity, and power consumption) that make it challenging to use cost-effective and energy-efficient security solutions. Recently, researchers have proposed a few Radio-Frequency Identification (RFID) based security solutions for MIoT. The use of RFID technology in securing IoT systems is rapidly increasing because it provides secure and lightweight safety mechanisms for these systems. More recently, authors have proposed a lightweight RFID mutual authentication (LRMI) protocol. The authors argue that LRMI meets the necessary security requirements for RFID systems, and the same applies to MIoT applications as well. In this paper, our contribution has two-folds, firstly we analyze the LRMI protocol's security to demonstrate that it is vulnerable to various attacks such as secret disclosure, reader impersonation, and tag traceability. Also, it is not able to preserve the anonymity of the tag and the reader. Secondly, we propose a new secure and lightweight mutual RFID authentication (SecLAP) protocol, which provides secure communication and preserves privacy in MIoT systems. Our security analysis shows that the SecLAP protocol is robust against de-synchronization, replay, reader/tag impersonation, and traceability attacks, and it ensures forward and backward data communication security. We use Burrows–Abadi–Needham (BAN) logic to validate the security features of SecLAP. Moreover, we compare SecLAP with the state-of-the-art and validate its performance through a Field Programmable Gate Array (FPGA) implementation, which shows that it is lightweight, consumes fewer resources on tags concerning computation functions, and requires less number of flows.

In recent years, researchers have proposed many authentication protocols for RFID tagged objects supporting tag ownership transfer. In this paper, first we present a tag traceability attack on a recent authentication protocol, called LSDARP+, proposed to enhance its predecessor, known as the LSDARP protocol. The LSDARP protocol is based on a sliding window mechanism with two important “authentication” and “ownership transfer” phases. We also show that LSDARP’s ownership transfer phase fails to protect new owner privacy. Moreover, we present our proposal for improving the security of these protocols. The proposed protocol has two phases, the “authentication” phase which is based on the sliding window mechanism, and a dedicated “generating new shared keys for new owner” phase. Finally, we show that our proposed protocol is secure and lightweight enough for the EPC-C1G2 standard.

Internet of Things (IoT) holds great promise for many life-improving applications like health-care systems. In IoT systems, providing secure authentication and key agreement scheme that considers compromised entities is an important issue. State-of-the-arts tackle this problem, but they fail to address compromised entity attack and have high computation cost. Motivated by these considerations, in this paper, we propose an energy-efficient proactive authentication and key agreement scheme called PAKIT for IoT systems. The security of PAKIT scheme is validated using the ProVerif tool. Moreover, the efficiency of PAKIT is compared with the predecessor schemes proposed for IoT systems. The results of the experiments show that PAKIT is efficient and suitable for real-world IoT applications by utilizing lightweight functions, such as hash and XOR.

In recent years, Radio Frequency Identification (RFID) systems are widely used in many applications. In some applications, the ownership of an RFID tag might change. To provide a solution, researchers have proposed several ownership transfer protocols based on encryption functions for RFID-tagged objects. In this paper, we consider the security of Kapoor and Piramuthu [3] ownership transfer protocol and Kapoor et al. [4] ownership transfer protocol. More precisely, we present de-synchronization attacks against these protocols. The success probability of all attacks is 1 while the complexity is only two runs of protocol. Finally, we present our suggestions to improve the security of these protocols.

The designers of Radio-Frequency IDentification (RFID) systems have a challenging task for proposing secure mutual authentication protocols for Internet of Things (IoT) applications. Recently, Fan et al. proposed a new lightweight RFID mutual authentication protocol in the journal of IEEE Transactions on Industrial Informatics. They claimed that their protocol meets necessary security properties for RFID systems and can be applied for IoT. In this paper, we analyze the security of this protocol and show that it is vulnerable against secret disclosure, reader impersonation and tag traceability attacks. Additionally, we show that in their protocol the anonymity of the tag does not held. keywords: RFID, IoT, Secret disclosure, Impersonation attack, Anonymity.

Heterogeneous wireless sensor networks (HWSNs) are employed in many real-time applications, such as Internet of sensors (IoS), Internet of vehicles (IoV), healthcare monitoring, and so on. As wireless sensor nodes have constrained computing, storage and communication capabilities, designing energy-efficient authentication protocols is a very important issue in wireless sensor network security. Recently, Amin et al. presented an untraceable and anonymous three-factor authentication (3FA) scheme for HWSNs and argued that their protocol is efficient and can withstand the common security threats in this sort of networks. In this article, we show how their protocol is not immune to user impersonation, de-synchronization and traceability attacks. In addition, an adversary can disclose session key under the typical assumption that sensors are not tamper-resistant. To overcome these drawbacks, we improve the Amin et al.'s protocol. First, we informally show that our improved scheme is secure against the most common attacks in HWSNs in which the attacks against Amin et al.'s protocol are part of them. Moreover, we verify formally our proposed protocol using the BAN logic. Compared with the Amin et al.'s scheme, the proposed protocol is both more efficient and more secure to be employed which renders the proposal suitable for HWSN networks.

Vehicular systems are an application of the internet of things (IoT) in which vehicles are equipped with sensors. In this system, sensors collect traffic information and send data to the nearest sink node. By analyzing this information special users, including police officers, can make better decisions. In this scenario, confidentiality and integrity of the information against active and passive attacks are vital. To provide these important security requirements in vehicular systems, researchers have proposed numerous authentication protocols. Recently, Mohit et al. proposed a new authentication protocol in vehicular systems and claimed that their protocol is secure against smartcard stolen attack, traceability attack and session key attack. However, in this paper we prove that their protocol is not only vulnerable against the aforementioned attacks but also it cannot preserve sensor node anonymity. Finally, we propose a new improved authentication protocol with better security; our experimental results show that our protocol not only is secure against the above attacks but also is still enough lightweight.

In recent years, RFID (radio-frequency identification) systems are widely used in many applications. One of the most important applications for this technology is the Internet of things (IoT). Therefore, researchers have proposed several authentication protocols that can be employed in RFID-based IoT systems, and they have claimed that their protocols can satisfy all security requirements of these systems. However, in RFID-based IoT systems we have mobile readers that can be compromised by the adversary. Due to this attack, the adversary can compromise a legitimate reader and obtain its secrets. So, the protocol designers must consider the security of their proposals even in the reader compromised scenario. In this paper, we consider the security of the ultra-lightweight RFID mutual authentication (ULRMAPC) protocol recently proposed by Fan et al. They claimed that their protocol could be applied in the IoT systems and provide strong security. However, in this paper we show that their protocol is vulnerable to denial of service, reader and tag impersonation and de-synchronization attacks. To provide a solution, we present a new authentication protocol, which is more secure than the ULRMAPC protocol and also can be employed in RFID-based IoT systems.

Design of ultra-lightweight authentication protocols for RFID systems conformed with the EPC Class-1 Generation-2 standard is still a challenging issue in RFID security. Recently, Maurya et al. have proposed a CRC based authentication protocol and claimed that their protocol can resist against all known attacks in RFID systems. However, in this paper we show that their protocol is vulnerable to tag impersonation attack. Moreover, we show that how an attacker can easily trace a target RFID tag. Our analyses show that the success probability of our attacks is “1” while the complexity is only one session eavesdropping, two XORs and one CRC computation. keywords: RFID, EPC-C1G2, Cyclic Redundancy Code, Ultra-lightweight, Authentication, Impersonation Attack, Traceability Attack.