Biblio

Vehicular Ad-hoc Network (VANET) can provide vehicle to vehicle (V2V) and vehicle to infrastructure (V2I) communications for efficient and safe transportation. The vehicles features high mobility, thus undergoing frequent handovers when they are moving, which introduces the significant overload on the network entities. To address the problem, the distributed mobility management (DMM) protocol for next generation mobile network has been proposed, which can be well combined with VANETs. Although the existing DMM solutions can guarantee the smooth handovers of vehicles, the security has not been fully considered in the mobility management. Moreover, the most of existing schemes cannot support group communication scenario. In this paper, we propose an efficient and secure group mobility management scheme based on the blockchain. Specifically, to reduce the handover latency and signaling cost during authentication, aggregate message authentication code (AMAC) and one-time password (OTP) are adopted. The security analysis and the performance evaluation results show that the proposed scheme can not only enhance the security functionalities but also support fast handover authentication.

Cloud storage offers a considerable efficiency and security to the user's data and provide high flexibility to the user. The hackers make attempt of several attacks to steal the data that increase the concern of data security in cloud. The Third Party Auditing (TPA) method is introduced to check the data integrity. There are several TPA methods developed to improve the privacy and efficiency of the data integrity checking method. Various methods involved in TPA, have been analyzed in this review in terms of function, security and overall performance. Merkel Hash Tree (MHT) method provides efficiency and security in checking the integrity of data. The computational overhead of the proof verify is also analyzed in this review. The communication cost of the most TPA methods observed as low and there is a need of improvement in security of the public auditing.

This paper presents a fully automated static analysis approach and a tool, Taint-Things, for the identification of tainted flows in SmartThings IoT apps. Taint-Things accurately identified all tainted flows reported by one of the state-of the-art tools with at least 4 times improved performance. In addition, our approach reports potential vulnerable tainted flow in a form of a concise security slice, which could provide security auditors with an effective and precise tool to pinpoint security issues in SmartThings apps under test.

In this fast moving world, every industry is advanced by a new technological paradigm called Internet of Things (IoT). It offers interconnectivity between the digital and the real world which will swiftly transform the style of doing business. It opens up a wide-ranging new array of dynamic opportunities in all industries and is fuelling innovation in every part of life. Due to the constrained nature of the devices in IoT environment, it is difficult to execute complex data encryption algorithms to enhance the security. Moreover, computation overhead caused by the existing cryptographic security algorithms is heavy and has to be minimized. To overcome these challenges, this paper presents the security analysis of the lightweight block cipher SAT\_Jo to ensure the data security in healthcare Internet of Things. It is based on SPN structure and runs for 31 rounds. It encrypts 64-bits of block length with key of 80 bits. Cadence NC-Verilog 5.1 is used for simulation and Cadence Encounter RTL Compiler v10.1 for synthesis. The implementations are synthesized for UMC 90 nm low-leakage Faraday library from technology libraries. Moreover, the proposed SAT\_Jo block cipher withstands in various attacks such as differential attack, linear attack and algebraic attack in healthcare IoT environment.

Forward secure proxy signature (FoSPS) solves the security drawback of private key exposure problem of generating the private key of each time interval. Directed signature scheme solves the public signature verification problem in traditional digital signature by designating the constant one as the signature verifier. Due to excellent properties, the two signature schemes have attracted the research of many experts. Recently, based on the Elliptic curve cryptography (ECC), a new FoSPS scheme and directed signature scheme were proposed. In this paper, we analyze the two schemes and present which the either of both schemes is insecure and do not satisfy the unforgeability. In other words, anyone is able to forge a valid signature but the one does not know the signer's secret key. In the same time, we give the main reasons why the enemy is able to forge the signature by analyzing the two schemes respectively. And we also present a simple improvement idea to overcome existing problems without adding extra computational cost which can make them applied in some environments such as e-medical information system.

In this article, we study the transmission secrecy performance of primary user in overlay cognitive wireless networks, in which an untrusted energy-limited secondary cooperative user assists the primary transmission to exchange for the spectrum resource. In the network, the information can be simultaneously transmitted through the direct and relay links. For the enhancement of primary transmission security, a maximum ratio combining (MRC) scheme is utilized by the receiver to exploit the two copies of source information. For the security analysis, we firstly derive the tight lower bound expression for secrecy outage probability (SOP). Then, three asymptotic expressions for SOP are also expressed to further analyze the impacts of the transmit power and the location of secondary cooperative node on the primary user information security. The findings show that the primary user information secrecy performance enhances with the improvement of transmit power. Moreover, the smaller the distance between the secondary node and the destination, the better the primary secrecy performance.

In recent years, real-world attacks against PKI take place frequently. For example, malicious domains' certificates issued by compromised CAs are widespread, and revoked certificates are still trusted by clients. In spite of a lot of research to improve the security of SSL/TLS connections, there are still some problems unsolved. On one hand, although log-based schemes provided certificate audit service to quickly detect CAs' misbehavior, the security and data consistency of log servers are ignored. On the other hand, revoked certificates checking is neglected due to the incomplete, insecure and inefficient certificate revocation mechanisms. Further, existing revoked certificates checking schemes are centralized which would bring safety bottlenecks. In this paper, we propose a blockchain-based public and efficient audit scheme for TLS connections, which is called Certchain. Specially, we propose a dependability-rank based consensus protocol in our blockchain system and a new data structure to support certificate forward traceability. Furthermore, we present a method that utilizes dual counting bloom filter (DCBF) with eliminating false positives to achieve economic space and efficient query for certificate revocation checking. The security analysis and experimental results demonstrate that CertChain is suitable in practice with moderate overhead.

To achieve its goals, ransomware needs to employ strong encryption, which in turn requires access to high-grade encryption keys. Over the evolution of ransomware, various techniques have been observed to accomplish the latter. Understanding the advantages and disadvantages of each method is essential to develop robust defense strategies. In this paper we explain the techniques used by ransomware to derive encryption keys and analyze the security of each approach. We argue that recovery of data might be possible if the ransomware cannot access high entropy randomness sources. As an evidence to support our theoretical results, we provide a decryptor program for a previously undefeated ransomware.

As cloud services greatly facilitate file sharing online, there's been a growing awareness of the security challenges brought by outsourcing data to a third party. Traditionally, the centralized management of cloud service provider brings about safety issues because the third party is only semi-trusted by clients. Besides, it causes trouble for sharing online data conveniently. In this paper, the blockchain technology is utilized for decentralized safety administration and provide more user-friendly service. Apart from that, Ciphertext-Policy Attribute Based Encryption is introduced as an effective tool to realize fine-grained data access control of the stored files. Meanwhile, the security analysis proves the confidentiality and integrity of the data stored in the cloud server. Finally, we evaluate the performance of computation overhead of our system.

Permissionless blockchains allow the execution of arbitrary programs (called smart contracts), enabling mutually untrusted entities to interact without relying on trusted third parties. Despite their potential, repeated security concerns have shaken the trust in handling billions of USD by smart contracts. To address this problem, we present Securify, a security analyzer for Ethereum smart contracts that is scalable, fully automated, and able to prove contract behaviors as safe/unsafe with respect to a given property. Securify's analysis consists of two steps. First, it symbolically analyzes the contract's dependency graph to extract precise semantic information from the code. Then, it checks compliance and violation patterns that capture sufficient conditions for proving if a property holds or not. To enable extensibility, all patterns are specified in a designated domain-specific language. Securify is publicly released, it has analyzed 18K contracts submitted by its users, and is regularly used to conduct security audits by experts. We present an extensive evaluation of Securify over real-world Ethereum smart contracts and demonstrate that it can effectively prove the correctness of smart contracts and discover critical violations.

In Smart Grids (SGs), data aggregation process is essential in terms of limiting packet size, data transmission amount and data storage requirements. This paper presents a novel Domingo-Ferrer additive privacy based Secure Data Aggregation (SDA) scheme for Fog Computing based SGs (FCSG). The proposed protocol achieves end-to-end confidentiality while ensuring low communication and storage overhead. Data aggregation is performed at fog layer to reduce the amount of data to be processed and stored at cloud servers. As a result, the proposed protocol achieves better response time and less computational overhead compared to existing solutions. Moreover, due to hierarchical architecture of FCSG and additive homomorphic encryption consumer privacy is protected from third parties. Theoretical analysis evaluates the effects of packet size and number of packets on transmission overhead and the amount of data stored in cloud server. In parallel with the theoretical analysis, our performance evaluation results show that there is a significant improvement in terms of data transmission and storage efficiency. Moreover, security analysis proves that the proposed scheme successfully ensures the privacy of collected data.

It is technically challenging to conduct a security analysis of a dynamic network, due to the lack of methods and techniques to capture different security postures as the network changes. Graphical Security Models (e.g., Attack Graph) are used to assess the security of network systems, but it typically captures a snapshot of a network state to carry out the security analysis. To address this issue, we propose a new Graphical Security Model named Time-independent Hierarchical Attack Representation Model (Ti-HARM) that captures security of multiple network states by taking into account the time duration of each network state and the visibility of network components (e.g., hosts, edges) in each state. By incorporating the changes, we can analyse the security of dynamic networks taking into account all the threats appearing in different network states. Our experimental results show that the Ti-HARM can effectively capture and assess the security of dynamic networks which were not possible using existing graphical security models.

In the smart grid, residents' electricity usage needs to be periodically measured and reported for the purpose of better energy management. At the same time, real-time collection of residents' electricity consumption may unfavorably incur privacy leakage, which has motivated the research on privacy-preserving aggregation of electricity readings. Most previous studies either rely on a trusted third party (TTP) or suffer from expensive computation. In this paper, we first reveal the privacy flaws of a very recent scheme pursing privacy preservation without relying on the TTP. By presenting concrete attacks, we show that this scheme has failed to meet the design goals. Then, for better privacy protection, we construct a new scheme called PMDA, which utilizes Shamir's secret sharing to allow smart meters to negotiate aggregation parameters in the absence of a TTP. Using only lightweight cryptography, PMDA efficiently supports multi-functional aggregation of the electricity readings, and simultaneously preserves residents' privacy. Theoretical analysis is provided with regard to PMDA's security and efficiency. Moreover, experimental data obtained from a prototype indicates that our proposal is efficient and feasible for practical deployment.

Moving Target Defence (MTD) has been recently proposed and is an emerging proactive approach which provides an asynchronous defensive strategies. Unlike traditional security solutions that focused on removing vulnerabilities, MTD makes a system dynamic and unpredictable by continuously changing attack surface to confuse attackers. MTD can be utilized in cloud computing to address the cloud's security-related problems. There are many literature proposing MTD methods in various contexts, but it still lacks approaches to evaluate the effectiveness of proposed MTD method. In this paper, we proposed a combination of Shuffle and Diversity MTD techniques and investigate on the effects of deploying these techniques from two perspectives lying on two groups of security metrics (i) system risk: which is the cloud providers' perspective and (ii) attack cost and return on attack: which are attacker's point of view. Moreover, we utilize a scalable Graphical Security Model (GSM) to enhance the security analysis complexity. Finally, we show that combining MTD techniques can improve both aforementioned two groups of security metrics while individual technique cannot.

In spite of numerous advantages of biometrics-based personal authentication systems over traditional security systems based on token or knowledge, they are vulnerable to attacks that can decrease their security considerably. In this paper, we propose a new hardware solution to protect biometric templates such as fingerprint. The proposed scheme is based on chaotic N × N grid multi-scroll system and it is implemented on Xilinx FPGA. The hardware implementation is achieved by applying numerical solution methods in our study, we use EM (Euler Method). Simulation and experimental results show that the proposed scheme allows a low cost image encryption for embedded systems while still providing a good trade-off between performance and hardware resources. Indeed, security analysis performed to the our scheme, is strong against known different attacks, such as: brute force, statistical, differential, and entropy. Therefore, the proposed chaos-based multiscroll encryption algorithm is suitable for use in securing embedded biometric systems.

The fifth generation of cellular networks (5G) will enable different use cases where security will be more critical than ever before (e.g. autonomous vehicles and critical IoT devices). Unfortunately, the new networks are being built on the certainty that security problems cannot be solved in the short term. Far from reinventing the wheel, one of our goals is to allow security software developers to implement and test their reactive solutions for the capillary network of 5G devices. Therefore, in this paper a solution for analysing proximity-based attacks in 5G environments is modelled and tested using OMNET++. The solution, named CRAT, is able to decouple the security analysis from the hardware of the device with the aim to extend the analysis of proximity-based attacks to different use-cases in 5G. We follow a high-level approach, in which the devices can take the role of victim, offender and guardian following the principles of the routine activity theory.

Smart Grid (SG) technology has been developing for years, which facilitates users with portable access to power through being applied in numerous application scenarios, one of which is the electric vehicle charging. In order to ensure the security of the charging process, users need authenticating with the smart meter for the subsequent communication. Although there are many researches in this field, few of which have endeavored to protect the anonymity and the untraceability of users during the authentication. Further, some studies consider the problem of user anonymity, but they are non-light-weight protocols, even some can not assure any fairness in key agreement. In this paper, we first points out that existing authentication schemes for Smart Grid are neither lack of critical security nor short of important property such as untraceability, then we propose a new two-factor lightweight user authentication scheme based on password and biometric. The authentication process of the proposed scheme includes four message exchanges among the user mobile, smart meter and the cloud server, and then a security one-time session key is generated for the followed communication process. Moreover, the scheme has some new features, such as the protection of the user's anonymity and untraceability. Security analysis shows that our proposed scheme can resist various well-known attacks and the performance analysis shows that compared to other three schemes, our scheme is more lightweight, secure and efficient.

Recent advances in pervasive computing have caused a rapid growth of the Smart Home market, where a number of otherwise mundane pieces of technology are capable of connecting to the Internet and interacting with other similar devices. However, with the lack of a commonly adopted set of guidelines, several IT companies are producing smart devices with their own proprietary standards, leading to highly heterogeneous Smart Home systems in which the interoperability of the present elements is not always implemented in the most straightforward manner. As such, understanding the cyber risk of these cyber-physical systems beyond the individual devices has become an almost intractable problem. This paper tackles this issue by introducing a Smart Home reference architecture which facilitates security analysis. Being composed by three viewpoints, it gives a high-level description of the various functions and components needed in a domestic IoT device and network. Furthermore, this document demonstrates how the architecture can be used to determine the various attack surfaces of a home automation system from which its key vulnerabilities can be determined.

Binary particle swarm optimization (BPSO) is a technique widely used to solve combinatorial problems. In this paper, we propose a variant of BPSO to find most likely attack paths in an attack graph. The aim is to find an attack path with the highest attack probability and least path length. In such combinatorial optimization problem, the set of feasible solutions is usually discrete and an exhaustive search may lead to unnecessary examination of those segments of the search space, which are assured to not include a solution. The paper introduces the concept of bounding the solution space of BPSO. The minimum and maximum value of each objective called bound of the solution is computed. The search space of BPSO is restricted within these solution bounds and hence we name our approach as bounded binary particle swarm optimization (BBPSO). By bounding the solution space, those particles of BPSO which are guaranteed to be infeasible are not considered for feasibility check. Experimental results show that the proposed approach provide a 50 percent performance improvement as compared to the conventional BPSO.

It is important to assess the cost benefits of IT security investments. Typically, this is done by manual risk assessment process. In this paper, we propose an approach to automate this using graphical security models (GSMs). GSMs have been used to assess the security of networked systems using various security metrics. Most of the existing GSMs assumed that networks are static, however, modern networks (e.g., Cloud and Software Defined Networking) are dynamic with changes. Thus, it is important to develop an approach that takes into account the dynamic aspects of networks. To this end, we automate security investments analysis of dynamic networks using a GSM named Temporal-Hierarchical Attack Representation Model (T-HARM) in order to automatically evaluate the security investments and their effectiveness for a given period of time. We demonstrate our approach via simulations.

Nowadays, Vehicular ad hoc network confronts many challenges in terms of security and privacy, due to the fact that data transmitted are diffused in an open access environment. However, highest of drivers want to maintain their information discreet and protected, and they do not want to share their confidential information. So, the private information of drivers who are distributed in this network must be protected against various threats that may damage their privacy. That is why, confidentiality, integrity and availability are the important security requirements in VANET. This paper focus on security threat in vehicle network especially on the availability of this network. Then we regard the rational attacker who decides to lead an attack based on its adversary's strategy to maximize its own attack interests. Our aim is to provide reliability and privacy of VANET system, by preventing attackers from violating and endangering the network. to ensure this objective, we adopt a tree structure called attack tree to model the attacker's potential attack strategies. Also, we join the countermeasures to the attack tree in order to build attack-defense tree for defending these attacks.

In modern cyber-physical systems and wireless sensor networks the complexity of crisis management processes is caused by a variety of software/hardware assets and communication protocols, the necessity of their collaborative function, possible inconsistency of data flows between particular devices and increased requirements to cyber-physical security. A crisis management oriented model of a communicational mobile network is constructed. A general architecture of network nodes by the use of XBee circuits, Arduino microcontrollers and connecting equipment are developed. An analysis of possible cyber-physical security events on the base of existing intruder models is performed. A series of experiments on modeling attacks on network nodes is conducted. Possible ways for attack revelations by means of components for security event collection and data correlation is discussed.

Security issues are crucial in a number of machine learning applications, especially in scenarios dealing with human activity rather than natural phenomena (e.g., information ranking, spam detection, malware detection, etc.). In such cases, learning algorithms may have to cope with manipulated data aimed at hampering decision making. Although some previous work addressed the issue of handling malicious data in the context of supervised learning, very little is known about the behavior of anomaly detection methods in such scenarios. In this contribution, we analyze the performance of a particular method–online centroid anomaly detection–in the presence of adversarial noise. Our analysis addresses the following security-related issues: formalization of learning and attack processes, derivation of an optimal attack, and analysis of attack efficiency and limitations. We derive bounds on the effectiveness of a poisoning attack against centroid anomaly detection under different conditions: attacker's full or limited control over the traffic and bounded false positive rate. Our bounds show that whereas a poisoning attack can be effectively staged in the unconstrained case, it can be made arbitrarily difficult (a strict upper bound on the attacker's gain) if external constraints are properly used. Our experimental evaluation, carried out on real traces of HTTP and exploit traffic, confirms the tightness of our theoretical bounds and the practicality of our protection mechanisms.

Named Data Networking (NDN) is a content-oriented future Internet architecture, which well suits the increasingly mobile and information-intensive applications that dominate today's Internet. NDN relies on in-network caching to facilitate content delivery. This makes it challenging to enforce access control since the content has been cached in the routers and the content producer has lost the control over it. Due to its salient advantages in content delivery, network coding has been introduced into NDN to improve content delivery effectiveness. In this paper, we design ACNC, the first Access Control solution specifically for Network Coding-based NDN. By combining a novel linear AONT (All Or Nothing Transform) and encryption, we can ensure that only the legitimate user who possesses the authorization key can successfully recover the encoding matrix for network coding, and hence can recover the content being transmitted. In addition, our design has two salient merits: 1) the linear AONT well suits the linear nature of network coding; 2) only one vector of the encoding matrix needs to be encrypted/decrypted, which only incurs small computational overhead. Security analysis and experimental evaluation in ndnSIM show that our design can successfully enforce access control on network coding-based NDN with an acceptable overhead.

Validating security properties of complex distributed systems is a challenging problem by itself, let alone when the work needs to be performed under tight budget and time constraints on prototype systems with components at various maturity levels. This paper described a tailored approach to security evaluations involving a strategic combination of model-based quantification, emulation, and logical argumentation. By customizing the evaluation to fit existing budget and timelines, validators can achieve the most appropriate validation process, trading off fidelity with coverage across a number of different defense components and different maturity levels. We successfully applied this process to the validation of an overlay proxy network, analyzing the impact of five different defense attributes (together with combinations thereof) on access path establishment and anonymity.