Biblio

This paper demonstrates that it is possible to execute sophisticated and powerful fault injection attacks on microcontrollers using low-cost equipment and readily available components. Earlier work had implied that powerful lasers and high grade optics frequently used to execute such attacks were being underutilized and that attacks were equally effective when using low-power settings and imprecise focus. This work has exploited these earlier findings to develop a low-cost laser workstation capable of generating multiple discrete faults with timing accuracy capable of targeting consecutive instruction cycles. We have shown that the capabilities of this new device exceed those of the expensive laboratory equipment typically used in related work. We describe a simplified fault model to categorize the effects of induced errors on running code and use it, along with the new device, to reevaluate the efficacy of different defensive coding techniques. This has enabled us to demonstrate an efficient hybrid defense that outperforms the individual defenses on our chosen target. This approach enables device programmers to select an appropriate compromise between the extremes of undefended code and unusable overdefended code, to do so specifically for their chosen device and without the need for prohibitively expensive equipment. This work has particular relevance in the burgeoning IoT world where many small companies with limited budgets are deploying low-cost microprocessors in ever more security sensitive roles.

Reducing latency in inter-process/inter-thread communication is one of the key challenges in parallel and distributed computing. This is because as the number of threads in an application increases, the communication overhead also increases. Moreover, the presence of background load further increases the latency. Reducing communication latency can have a significant impact on multi-threaded application performance in multi-core environments. In a wide-range of applications that utilize queueing mechanism, inter-process/ inter-thread communication typically involves enqueuing and dequeuing. This paper presents a queueing techniques called eLCRQ, which is a lock-free block-when-necessary multi-producer multi-consumer (MPMC) FIFO queue. It is designed for scenarios where the queue can randomly and frequently become empty during runtime. By combining lock-free performance with blocking resource efficiency, it delivers improved performance. Specifically, it results in a 1.7X reduction in latency and a 2.3X reduction in CPU usage when compared to existing message-passing mechanisms including PIPE and Sockets while running on multi-core Linux based systems. The proposed scheme also provides a 3.4X decrease in CPU usage while maintaining comparable latency when compared to other (MPMC) lock-free queues in low load scenarios. Our work is based on open-source Linux and support libraries.

Data races occur when two threads fail to use proper synchronization when accessing shared data. In kernel file systems, which are highly concurrent by design, data races are common mistakes and often wreak havoc on the users, causing inconsistent states or data losses. Prior fuzzing practices on file systems have been effective in uncovering hundreds of bugs, but they mostly focus on the sequential aspect of file system execution and do not comprehensively explore the concurrency dimension and hence, forgo the opportunity to catch data races.In this paper, we bring coverage-guided fuzzing to the concurrency dimension with three new constructs: 1) a new coverage tracking metric, alias coverage, specially designed to capture the exploration progress in the concurrency dimension; 2) an evolution algorithm for generating, mutating, and merging multi-threaded syscall sequences as inputs for concurrency fuzzing; and 3) a comprehensive lockset and happens-before modeling for kernel synchronization primitives for precise data race detection. These components are integrated into Krace, an end-to-end fuzzing framework that has discovered 23 data races in ext4, btrfs, and the VFS layer so far, and 9 are confirmed to be harmful.

Space-air-ground integrated network (SAGIN) is emerged as a versatile computing and traffic architecture in recent years. Though SAGIN brings many significant benefits for modern communication and computing services, there are many unprecedented challenges in SAGIN. The one critical challenge in SAGIN is the data security. In SAGIN, because the data will be stored in cleartext on cloud, the sensitive data may suffer from the illegal access by the unauthorized users even the untrusted cloud servers (CSs). Ciphertext-policy attribute-based encryption (CP-ABE), which is a type of attribute-based encryption (ABE), has been regarded as a promising solution to the critical challenge of the data security on cloud. But there are two main blemishes in traditional CP-ABE. The first one is that there is only one attribute authority (AA) in CP-ABE. If the single AA crashs down, the whole system will be shut down. The second one is that the AA cannot effectively manage the life cycle of the users’ private keys. If a user on longer has one attribute, the AA cannot revoke the user’s private key of this attribute. This means the user can still decrypt some ciphertexts using this invalid attribute. In this paper, to solve the two flaws mentioned above, we propose a multi-authority CP-ABE (MA-CP-ABE) scheme with the dynamical key revocation (DKR). Our key revocation supports both user revocation and attribute revocation. And the our revocation is time friendly. What’s more, by using our dynamically tag-based revocation algorithm, AAs can dynamically and directly re-enable or revoke the invalid attributes to users. Finally, by evaluating and implementing our scheme, we can observe that our scheme is more comprehensive and practical for cloud applications in SAGIN.

Equivalence checking is one of the most scalable and useful verification techniques in industry. NULL Convention Logic (NCL) circuits utilize dual-rail signals (i.e., two wires to represent one bit of DATA), where the wires are inverses of each other during a DATA wavefront. In this paper, a technique that exploits this invariant at NCL register boundaries is proposed to improve the efficiency of equivalence verification of NCL circuits.

A neural key exchange is a secret key exchange technique based on neural synchronization of the neural network. Since the neural key exchange is based on synchronizing weights within the neural network structure, the security of the algorithm does not depend on the attacker's computational capabilities. However, due to the neural key exchange's repetitive mutual-learning processes, using explicit user authentication methods -such as a public key certificate- is inefficient due to high communication overhead. Implicit authentication based on information that only authorized users know can significantly reduce overhead in communications. However, there was a lack of realistic methods to distribute secret information for authentication among authorized users. In this paper, we propose the concept idea of distributing shared secret values for implicit authentication based on the randomness of the public blockchain. Moreover, we present a method to prevent the unintentional disclosure of shared secret values to third parties in the network due to the transparency of the blockchain.

This research is dedicated to the development of a prototype of open infrastructure for users’ internet traffic filtering on a browser level. We described the advantages of a distributed approach in comparison with current centralized solutions. Besides, we suggested a solution to define the optimum size for a URL storage block in Ethereum network. This solution may be used for the development of infrastructure of DApps applications on Ethereum network in future. The efficiency of the suggested approach is supported by several experiments.

Language-based information-flow control (IFC) techniques often rely on special purpose, ad-hoc primitives to address different covert channels that originate in the runtime system, beyond the scope of language constructs. Since these piecemeal solutions may not compose securely, there is a need for a unified mechanism to control covert channels. As a first step towards this goal, we argue for the design of a general interface that allows programs to safely interact with the runtime system and the available computing resources. To coordinate the communication between programs and the runtime system, we propose the use of asynchronous exceptions (interrupts), which, to the best of our knowledge, have not been considered before in the context of IFC languages. Since asynchronous exceptions can be raised at any point during execution-often due to the occurrence of an external event-threads must temporarily mask them out when manipulating locks and shared data structures to avoid deadlocks and, therefore, breaking program invariants. Crucially, the naive combination of asynchronous exceptions with existing features of IFC languages (e.g., concurrency and synchronization variables) may open up new possibilities of information leakage. In this paper, we present MACasync, a concurrent, statically enforced IFC language that, as a novelty, features asynchronous exceptions. We show how asynchronous exceptions easily enable (out of the box) useful programming patterns like speculative execution and some degree of resource management. We prove that programs in MACasync satisfy progress-sensitive non-interference and mechanize our formal claims in the Agda proof assistant.

Bitcoin was the first successful decentralized cryptocurrency and remains the most popular of its kind to this day. Despite the benefits of its blockchain, Bitcoin still faces serious scalability issues, most importantly its ever-increasing blockchain size. While alternative designs introduced schemes to periodically create snapshots and thereafter prune older blocks, already-deployed systems such as Bitcoin are often considered incapable of adopting corresponding approaches. In this work, we revise this popular belief and present CoinPrune, a snapshot-based pruning scheme that is fully compatible with Bitcoin. CoinPrune can be deployed through an opt-in velvet fork, i.e., without impeding the established Bitcoin network. By requiring miners to publicly announce and jointly reaffirm recent snapshots on the blockchain, CoinPrune establishes trust into the snapshots' correctness even in the presence of powerful adversaries. Our evaluation shows that CoinPrune reduces the storage requirements of Bitcoin already by two orders of magnitude today, with further relative savings as the blockchain grows. In our experiments, nodes only have to fetch and process 5GiB instead of 230GiB of data when joining the network, reducing the synchronization time on powerful devices from currently 5h to 46min, with even more savings for less powerful devices.

This paper investigates the use of BeagleBone Black Wireless single-board Linux computers with Long Range (LoRa) transceivers to send and receive information in a mesh network while one of the transmitting/receiving nodes is acting as a relay in the system. An experiment is conducted to examine how long each LoRa node needed to learn the transmission intervals of any other transmitting nodes on the network and to synchronize with the other nodes prior to transmission. The spread factor, bandwidth, and coding rate are all varied for a total of 18 different combinations. A link to the Python code used on the BeagleBone Black is provided at the end of this paper. The best parameter combinations for each individual node and for the system as a whole is investigated. Additional experiments and applications of this technology are explored in the conclusions.

In this work, we propose a novel approach for decentralized identifier distribution and synchronization in networks. The protocol generates network entity identifiers composed of timestamps and cryptographically secure random values with a significant reduction of collision probability. The distribution is inspired by Unique Universal Identifiers and Timestamp-based Concurrency Control algorithms originating from database applications. We defined fundamental requirements for the distribution, including: uniqueness, accuracy of distribution, optimal timing behavior, scalability, small impact on network load for different operation modes and overall compliance to common network security objectives. An implementation of the proposed approach is evaluated and the results are presented. Originally designed for a domain of proactive defense strategies known as Moving Target Defense, the general architecture of the protocol enables arbitrary applications where identifier distributions in networks have to be decentralized, rapid and secure.

The Precision Time Protocol is essential for many time-sensitive and time-aware applications. However, it was never designed for security, and despite various approaches to harden this protocol against manipulation, it is still prone to cyber-attacks. Here Advanced Persistent Threats (APT) are of particular concern, as they may stealthily and over extended periods of time manipulate computer clocks that rely on the accurate functioning of this protocol. Simulating such attacks is difficult, as it requires firmware manipulation of network and PTP infrastructure components. Therefore, this paper proposes and demonstrates a programmable Man-in-the-Middle (pMitM) and a programmable injector (pInj) device that allow the implementation of a variety of attacks, enabling security researchers to quantify the impact of APTs on time synchronisation.

In network communication domain, one of the most widely used protocol for encrypting data and securing communications is the IPSec protocol. The design of this protocol is based on two main phases which are: exchanging keys phase and transferring data phase. In this paper we focus on enhancing the exchanging keys phase which is included in the security association (SA), using a chaotic cryptosystem. Initially IPSec is based on the Internet Key Exchange (IKE) protocol for establishing the SA. Actually IKE protocol is in charge for negotiating the connection and for authenticating both nodes. However; using IKE gives rise to a major problem related to security attack such as the Man in the Middle Attack. In this paper, we propose a chaotic cryptosystem solution to generate SA file for the connected nodes of the network. By solving a 4-Dimension chaotic system, a SA file that includes 128-bit keys will be established. The proposed solution is implemented and tested using FPGA boards.

In this work, an asymmetric cryptography method for information security was developed, inspired by the fact that the human body generates chaotic signals, and these signals can be used to create sequences of random numbers. Encryption circuit was implemented in a Reconfigurable Hardware (FPGA). To encode and decode an image, the chaotic synchronization between two dynamic systems, such as Hopfield neural networks (HNNs), was used to simulate chaotic signals. The notion of Homotopy, an argument of topological nature, was used for the synchronization. The results show efficiency when compared to state of the art, in terms of image correlation, histogram analysis and hardware implementation.

Physical fingerprinting is a trending domain in wireless security. Those methods aim at identifying transmitters based on the subtle variations existing in their handling of a communication protocol. They can provide an additional authentication layer, hard to emulate, to improve the security of systems. Software Defined Radios (SDR) are a tool of choice for the fingerprinting, as they virtually enable the analysis of any wireless communication scheme. However, they require expensive computations, and are still complex to handle by newcomers. In this paper, we use low cost SDR to propose a physical-layer fingerprinting approach, that allows recognition of the model of a device performing a Bluetooth scan, with more than 99.8% accuracy in a set of ten devices.

Bluetooth Classic (BT) remains the de facto connectivity technology in car stereo systems, wireless headsets, laptops, and a plethora of wearables, especially for applications that require high data rates, such as audio streaming, voice calling, tethering, etc. Unlike in Bluetooth Low Energy (BLE), where address randomization is a feature available to manufactures, BT addresses are not randomized because they are largely believed to be immune to tracking attacks. We analyze the design of BT and devise a robust de-anonymization technique that hinges on the apparently benign information leaking from frame encoding, to infer a piconet's clock, hopping sequence, and ultimately the Upper Address Part (UAP) of the master device's physical address, which are never exchanged in clear. Used together with the Lower Address Part (LAP), which is present in all frames transmitted, this enables tracking of the piconet master, thereby debunking the privacy guarantees of BT. We validate this attack by developing the first Software-defined Radio (SDR) based sniffer that allows full BT spectrum analysis (79 MHz) and implements the proposed de-anonymization technique. We study the feasibility of privacy attacks with multiple testbeds, considering different numbers of devices, traffic regimes, and communication ranges. We demonstrate that it is possible to track BT devices up to 85 meters from the sniffer, and achieve more than 80% device identification accuracy within less than 1 second of sniffing and 100% detection within less than 4 seconds. Lastly, we study the identified privacy attack in the wild, capturing BT traffic at a road junction over 5 days, demonstrating that our system can re-identify hundreds of users and infer their commuting patterns.

The major challenge of Real Time Protocol is to balance efficiency and fairness over limited bandwidth. MPTCP has proved to be effective for multimedia and real time networks. Ideally, an MPTCP sender should couple the subflows sharing the bottleneck link to provide TCP friendliness. However, existing shared bottleneck detection scheme either utilize end-to-end delay without consideration of multiple bottleneck scenario, or identify subflows on switch at the expense of operation overhead. In this paper, we propose a lightweight yet accurate approach, EMPTCP, to detect shared bottleneck. EMPTCP uses the widely deployed ECN scheme to capture the real congestion state of shared bottleneck, while at the same time can be transparently utilized by various enhanced MPTCP protocols. Through theory analysis, simulation test and real network experiment, we show that EMPTCP achieves higher than 90% accuracy in shared bottleneck detection, thus improving the network efficiency and fairness.

We have proposed the Media Access Control method based on the Synchronization Phenomena of coupled oscillators (SP-MAC) to improve a total throughput of wireless terminals connected to a Access Point. SP-MAC can avoid the collision of data frames that occur by applying Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) based on IEEE 802.11 in Wireless local area networks (WLAN). Furthermore, a new throughput guarantee control method based on SP-MAC has been proposed. This method enable each terminal not only to avoid the collision of frames but also to obtain the requested throughput by adjusting the parameters of SP-MAC. In this paper, we propose a new throughput control method that realizes the fairness among groups of terminals that use the different TCP versions, by taking the advantage of our method that is able to change acquired throughput by adjusting parameters. Moreover, we confirm the effectiveness of the proposed method by the simulation evaluation.

Concurrency vulnerabilities are extremely harmful and can be frequently exploited to launch severe attacks. Due to the non-determinism of multithreaded executions, it is very difficult to detect them. Recently, data race detectors and techniques based on maximal casual model have been applied to detect concurrency vulnerabilities. However, the former are ineffective and the latter report many false negatives. In this paper, we present CONVUL, an effective tool for concurrency vulnerability detection. CONVUL is based on exchangeable events, and adopts novel algorithms to detect three major kinds of concurrency vulnerabilities. In our experiments, CONVUL detected 9 of 10 known vulnerabilities, while other tools only detected at most 2 out of these 10 vulnerabilities. The 10 vulnerabilities are available at https://github.com/mryancai/ConVul.

In this paper, the cybersecurity of distributed secondary voltage control of AC microgrids is addressed. A resilient approach is proposed to mitigate the negative impacts of cyberthreats on the voltage and reactive power control of Distributed Energy Resources (DERs). The proposed secondary voltage control is inspired by the resilient flocking of a mobile robot team. This approach utilizes a virtual time-varying communication graph in which the quality of the communication links is virtualized and determined based on the synchronization behavior of DERs. The utilized control protocols on DERs ensure that the connectivity of the virtual communication graph is above a specific resilience threshold. Once the resilience threshold is satisfied the Weighted Mean Subsequence Reduced (WMSR) algorithm is applied to satisfy voltage restoration in the presence of malicious adversaries. A typical microgrid test system including 6 DERs is simulated to verify the validity of proposed resilient control approach.

This work presents a new method of encrypting and decrypting speech based on a chaotic key generator. The proposed scheme takes advantage of the best features of chaotic systems. In the proposed method, the input speech signal is converted into an image which is ciphered by an encryption function using a chaotic key matrix generated from a fractional-order chaotic map. Based on a deadbeat observer, the exact synchronization of system used is established, and the decryption is performed. Different analysis are applied for analyzing the effectiveness of the encryption system. The obtained results confirm that the proposed system offers a higher level of security against various attacks and holds a strong key generation mechanism for satisfactory speech communication.

In network communication domain, one of the most widely used protocol for encrypting data and securing communications is the IPSec protocol. The design of this protocol is based on two main phases which are: exchanging keys phase and transferring data phase. In this paper we focus on enhancing the exchanging keys phase which is included in the security association (SA), using a chaotic cryptosystem. Initially IPSec is based on the Internet Key Exchange (IKE) protocol for establishing the SA. Actually IKE protocol is in charge for negotiating the connection and for authenticating both nodes. However; using IKE gives rise to a major problem related to security attack such as the Man in the Middle Attack. In this paper, we propose a chaotic cryptosystem solution to generate SA file for the connected nodes of the network. By solving a 4-Dimension chaotic system, a SA file that includes 128-bit keys will be established. The proposed solution is implemented and tested using FPGA boards.

In this work, an asymmetric cryptography method for information security was developed, inspired by the fact that the human body generates chaotic signals, and these signals can be used to create sequences of random numbers. Encryption circuit was implemented in a Reconfigurable Hardware (FPGA). To encode and decode an image, the chaotic synchronization between two dynamic systems, such as Hopfield neural networks (HNNs), was used to simulate chaotic signals. The notion of Homotopy, an argument of topological nature, was used for the synchronization. The results show efficiency when compared to state of the art, in terms of image correlation, histogram analysis and hardware implementation.

Generalized chaos systems have more complex dynamic behavior than conventional chaos systems. If a generalized response system can be synchronized with a conventional drive system, the flexible control parameters and unpredictable synchronization state will increase significantly. The study first constructs a four-dimensional nonlinear dynamic equation with quadratic variables as a drive system. The numerical simulation and analyses of the Lyapunov exponent show that it is also a chaotic system. Based on the generalized chaos synchronization (GCS) theory, a four-dimensional diffeomorphism function is designed, and the corresponding GCS response system is generated. Simultaneously, the structural and synchronous circuits of information interaction and control are constructed with Multisim™ software, with the circuit simulation resulting in a good agreement with the numerical calculations. In order to verify the practical effect of generalized synchronization, an RGB digital image secure communication scheme is proposed. We confuse a 24-bit true color image with the designed GCS system, extend the original image to 48-bits, analyze the scheme security from keyspace, key sensitivity and non-symmetric identity authentication, classical types of attacks, and statistical average from the histogram, image correlation. The research results show that this GCS system is simple and feasible, and the encryption algorithm is closely related to the confidential information, which can resist the differential attack. The scheme is suitable to be applied in network images or other multimedia safe communications.

MAC using a counter value in message authentication for in-vehicle network prevents replay attack. When synchronization deviation of the counter value occurs between the sender and receiver, a message cannot be authenticated correctly because the generated MACs are different. Thus, a counter synchronization method has been proposed. In addition, injection and replay attack of a synchronization message for the synchronization method have been performed. However, DoS attack on the synchronization method has not been conducted. This study performs DoS attack in order to evaluate security of the synchronization method. Experimental results reveal the vulnerability of the synchronization method against DoS attack.