Biblio

Radio network information is leaked well beyond the perimeter in which the radio network is deployed. We investigate attacks where person location can be inferred using the radio characteristics of wireless links (e.g., the received signal strength). An attacker can deploy a network of receivers which measure the received signal strength of the radio signals transmitted by the legitimate wireless devices inside a perimeter, allowing the attacker to learn the locations of people moving in the vicinity of the devices inside the perimeter. In this paper, we develop the first solution to this location privacy problem where neither the attacker nodes nor the tracked moving object transmit any RF signals. We first model the radio network leakage attack using a Stackelberg game. Next, we define utility and cost functions related to the defender and attacker actions. Last, using our utility and cost functions, we find the optimal strategy for the defender by applying a greedy method. We evaluate our game theoretic framework using experiments and find that our approach significantly reduces the chance of an attacker determining the location of people inside a perimeter.

This paper presents an architecture for a discrete, high-entropy hardware random number generator. Because it is constructed out of simple hardware components, its operation is transparent and auditable. Using avalanche noise, a non-deterministic physical phenomenon, the circuit is inherently probabilistic and resists adversarial control. Furthermore, because it compares the outputs from two matched noise sources, it rejects environmental disturbances like RF energy and power supply ripple. The resulting hardware produces more than 0.98 bits of entropy per sample, is inexpensive, has a small footprint, and can be disabled to conserve power when not in use.

A major component of modern vehicles is the infotainment system, which interfaces with its drivers and passengers. Other mobile devices, such as handheld phones and laptops, can relay information to the embedded infotainment system through Bluetooth and vehicle WiFi. The ability to extract information from these systems would help forensic analysts determine the general contents that is stored in an infotainment system. Based off the data that is extracted, this would help determine what stored information is relevant to law enforcement agencies and what information is non-essential when it comes to solving criminal activities relating to the vehicle itself. This would overall solidify the Intelligent Transport System and Vehicular Ad Hoc Network infrastructure in combating crime through the use of vehicle forensics. Additionally, determining the content of these systems will allow forensic analysts to know if they can determine anything about the end-user directly and/or indirectly.

Content Security Policy (CSP) is powerful client-side security layer that helps in mitigating and detecting wide ranges of Web attacks including cross-site scripting (XSS). However, utilizing CSP by site administrators is a fallible process and may require significant changes in web application code. In this paper, we propose an approach to help site administers to overcome these limitations in order to utilize the full benefits of CSP mechanism which leads to more immune sites from XSS. The algorithm is implemented as a plugin. It does not interfere with the Web application original code. The plugin can be “installed” on any other web application with minimum efforts. The algorithm can be implemented as part of Web Server layer, not as part of the business logic layer. It can be extended to support generating CSP for contents that are modified by JavaScript after loading. Current approach inspects the static contents of URLs.

Cyber-physical system integrity requires both hardware and software security. Many of the cyber attacks are successful as they are designed to selectively target a specific hardware or software component in an embedded system and trigger its failure. Existing security measures also use attack vector models and isolate the malicious component as a counter-measure. Isolated security primitives do not provide the overall trust required in an embedded system. Trust enhancements are proposed to a hardware security platform, where the trust specifications are implemented in both software and hardware. This distribution of trust makes it difficult for a hardware-only or software-only attack to cripple the system. The proposed approach is applied to a smart grid application consisting of third-party soft IP cores, where an attack on this module can result in a blackout. System integrity is preserved in the event of an attack and the anomalous behavior of the IP core is recorded by a supervisory module. The IP core also provides a snapshot of its trust metric, which is logged for further diagnostics.

Systems-on-a-Chip are among the best-performing and complete solutions for complex electronic systems. This is also true in the field of network security, an application requiring high performance with low resource usage. This work presents an Advanced Encryption Standard implementation for Systems-on-a-Chip using as a reference the Cipher Block Chaining mode. In particular, a flexible interface based and the Advanced Peripheral Bus to integrate the encryption algorithm with any kind of processor is presented. The hardware-software approach of the architecture is also analyzed and described. The final system was integrated on a Xilinx Zynq 7000 to prototype and evaluate the idea. Results show that our solution demonstrates good performance and flexibility with low resource usage, occupying less than 2% of the Zynq 7000 with a throughput of 320 Mbps. The architecture is suitable when implementations of symmetric encryption algorithms for modern Systems-on-a-Chip are required.

Embedded systems are becoming increasingly complex as designers integrate different functionalities into a single application for execution on heterogeneous hardware platforms. In this work we propose a system-level security approach in order to provide isolation of tasks without the need to trust a central authority at run-time. We discuss security requirements that can be found in complex embedded systems that use heterogeneous execution platforms, and by regulating memory access we create mechanisms that allow safe use of shared IP with direct memory access, as well as shared libraries. We also present a prototype Isolation Unit that checks memory transactions and allows for dynamic configuration of permissions.

Zero-day attacks continue to challenge the enterprise network security defense. A zero-day attack path is formed when a multi-step attack contains one or more zero-day exploits. Detecting zero-day attack paths in time could enable early disclosure of zero-day threats. In this paper, we propose a probabilistic approach to identify zero-day attack paths and implement a prototype system named ZePro. An object instance graph is first built from system calls to capture the intrusion propagation. To further reveal the zero-day attack paths hiding in the instance graph, our system constructs an instance-graph-based Bayesian network. By leveraging intrusion evidence, the Bayesian network can quantitatively compute the probabilities of object instances being infected. The object instances with high infection probabilities reveal themselves and form the zero-day attack paths. The experiment results show that our system can effectively identify zero-day attack paths.

A cross-layer secure communication scheme for multiple input multiple output (MIMO) system based on spatial modulation (SM) is proposed in this paper. The proposed scheme combined the upper layer stream cipher with the distorted signal design of the MIMO spatial modulation system in the physical layer to realize the security information transmission, which is called cross-layer secure communication system. Simulation results indicate that the novel scheme not only further ensure the legitimate user an ideal reception demodulation performance as the original system, but also make the eavesdropper' error rate stable at 0.5. The novel system do not suffer from a significant increasing complexity.

Multivariate public key cryptosystem acts as a signature system rather than encryption system due to the minus mode used in system. A multivariate encryption system with determinate equations in central map and chaotic shell protection for central map and affine map is proposed in this paper. The outputs of two-dimension chaotic system are discretized on a finite field to disturb the central map and affine map in multivariate cryptosystem. The determined equations meet the shortage of indeterminate equations in minus mode and make the general attack methods are out of tenable condition. The analysis shows the proposed multivariate symmetric encryption system based on chaotic shell is able to resist general attacks.

Separation of network control from devices in Software Defined Network (SDN) allows for centralized implementation and management of security policies in a cloud computing environment. The ease of programmability also makes SDN a great platform implementation of various initiatives that involve application deployment, dynamic topology changes, and decentralized network management in a multi-tenant data center environment. Dynamic change of network topology, or host reconfiguration in such networks might require corresponding changes to the flow rules in the SDN based cloud environment. Verifying adherence of these new flow policies in the environment to the organizational security policies and ensuring a conflict free environment is especially challenging. In this paper, we extend the work on rule conflicts from a traditional environment to an SDN environment, introducing a new classification to describe conflicts stemming from cross-layer conflicts. Our framework ensures that in any SDN based cloud, flow rules do not have conflicts at any layer; thereby ensuring that changes to the environment do not lead to unintended consequences. We demonstrate the correctness, feasibility and scalability of our framework through a proof-of-concept prototype.

Malware detection has been widely studied by analysing either file dropping relationships or characteristics of the file distribution network. This paper, for the first time, studies a global heterogeneous malware delivery graph fusing file dropping relationship and the topology of the file distribution network. The integration offers a unique ability of structuring the end-to-end distribution relationship. However, it brings large heterogeneous graphs to analysis. In our study, an average daily generated graph has more than 4 million edges and 2.7 million nodes that differ in type, such as IPs, URLs, and files. We propose a novel Bayesian label propagation model to unify the multi-source information, including content-agnostic features of different node types and topological information of the heterogeneous network. Our approach does not need to examine the source codes nor inspect the dynamic behaviours of a binary. Instead, it estimates the maliciousness of a given file through a semi-supervised label propagation procedure, which has a linear time complexity w.r.t. the number of nodes and edges. The evaluation on 567 million real-world download events validates that our proposed approach efficiently detects malware with a high accuracy.

In this research paper, we present a function-based methodology to evaluate the resilience of gas pipeline systems under two different cyber-physical attack scenarios. The first attack scenario is the pressure integrity attack on the natural gas high-pressure transmission pipeline. Through simulations, we have analyzed the cyber attacks that propagate from cyber to the gas pipeline physical domain, the time before which the SCADA system should respond to such attacks, and finally, an attack which prevents the response of the system. We have used the combined results of simulations of a wireless mesh network for remote terminal units and of a gas pipeline simulation to measure the shortest Time to Criticality (TTC) parameter; the time for an event to reach the failure state. The second attack scenario describes how a failure of a cyber node controlling power grid functionality propagates from cyber to power to gas pipeline systems. We formulate this problem using a graph-theoretic approach and quantify the resilience of the networks by percentage of connected nodes and the length of the shortest path between them. The results show that parameters such as TTC, power distribution capacity of the power grid nodes and percentage of the type of cyber nodes compromised, regulate the efficiency and resilience of the power and gas networks. The analysis of such attack scenarios helps the gas pipeline system administrators design attack remediation algorithms and improve the response of the system to an attack.

The Internet of Things (IoT) is a design implementation of embedded system design that connects a variety of devices, sensors, and physical objects to a larger connected network (e.g. the Internet) which requires human-to-human or human-to-computer interaction. While the IoT is expected to expand the user's connectivity and everyday convenience, there are serious security considerations that come into account when using the IoT for distributed authentication. Furthermore the incorporation of biometrics to IoT design brings about concerns of cost and implementing a 'user-friendly' design. In this paper, we focus on the use of electrocardiogram (ECG) signals to implement distributed biometrics authentication within an IoT system model. Our observations show that ECG biometrics are highly reliable, more secure, and easier to implement than other biometrics.

In this paper we describe a system that allows the real time creation of firewall rules in response to geographic and political changes in the control-plane. This allows an organization to mitigate data exfiltration threats by analyzing Border Gateway Protocol (BGP) updates and blocking packets from being routed through problematic jurisdictions. By inspecting the autonomous system paths and referencing external data sources about the autonomous systems, a BGP participant can infer the countries that traffic to a particular destination address will traverse. Based on this information, an organization can then define constraints on its egress traffic to prevent sensitive data from being sent via an untrusted region. In light of the many route leaks and BGP hijacks that occur today, this offers a new option to organizations willing to accept reduced availability over the risk to confidentiality. Similar to firewalls that allow organizations to block traffic originating from specific countries, our approach allows blocking outbound traffic from transiting specific jurisdictions. To illustrate the efficacy of this approach, we provide an analysis of paths to various financial services IP addresses over the course of a month from a single BGP vantage point that quantifies the frequency of path alterations resulting in the traversal of new countries. We conclude with an argument for the utility of country-based egress policies that do not require the cooperation of upstream providers.

Motivated by the impossibility of achieving fairness in secure computation [Cleve, STOC 1986], recent works study a model of fairness in which an adversarial party that aborts on receiving output is forced to pay a mutually predefined monetary penalty to every other party that did not receive the output. These works show how to design protocols for secure computation with penalties that tolerate an arbitrary number of corruptions. In this work, we improve the efficiency of protocols for secure computation with penalties in a hybrid model where parties have access to the "claim-or-refund" transaction functionality. Our first improvement is for the ladder protocol of Bentov and Kumaresan (Crypto 2014) where we improve the dependence of the script complexity of the protocol (which corresponds to miner verification load and also space on the blockchain) on the number of parties from quadratic to linear (and in particular, is completely independent of the underlying function). Our second improvement is for the see-saw protocol of Kumaresan et al. (CCS 2015) where we reduce the total number of claim-or-refund transactions and also the script complexity from quadratic to linear in the number of parties.

Physical Unclonable Functions (PUFs) measure manufacturing variations inside integrated circuits to derive internal secrets during run-time and avoid to store secrets permanently in non-volatile memory. PUF responses are noisy such that they require error correction to generate reliable cryptographic keys. To date, when needed one single key is reproduced in the field and always used, regardless of its reliability. In this work, we compute online reliability information for a reproduced key and perform multiple PUF readout and error correction steps in case of an unreliable result. This permits to choose the most reliable key among multiple derived key candidates with different corrected error patterns. We achieve the same average key error probability from less PUF response bits with this approach. Our proof of concept design for a popular reference scenario uses Differential Sequence Coding (DSC) and a Viterbi decoder with reliability output information. It requires 39% less PUF response bits and 16% less helper data bits than the regular approach without the option for multiple readouts.

Cryptocurrencies, such as Bitcoin and 250 similar alt-coins, embody at their core a blockchain protocol –- a mechanism for a distributed network of computational nodes to periodically agree on a set of new transactions. Designing a secure blockchain protocol relies on an open challenge in security, that of designing a highly-scalable agreement protocol open to manipulation by byzantine or arbitrarily malicious nodes. Bitcoin's blockchain agreement protocol exhibits security, but does not scale: it processes 3–7 transactions per second at present, irrespective of the available computation capacity at hand. In this paper, we propose a new distributed agreement protocol for permission-less blockchains called ELASTICO. ELASTICO scales transaction rates almost linearly with available computation for mining: the more the computation power in the network, the higher the number of transaction blocks selected per unit time. ELASTICO is efficient in its network messages and tolerates byzantine adversaries of up to one-fourth of the total computational power. Technically, ELASTICO uniformly partitions or parallelizes the mining network (securely) into smaller committees, each of which processes a disjoint set of transactions (or "shards"). While sharding is common in non-byzantine settings, ELASTICO is the first candidate for a secure sharding protocol with presence of byzantine adversaries. Our scalability experiments on Amazon EC2 with up to \$1, 600\$ nodes confirm ELASTICO's theoretical scaling properties.

The blockchain emerges as an innovative tool which proves to be useful in a number of application scenarios. A number of large industrial players, such as IBM, Microsoft, Intel, and NEC, are currently investing in exploiting the blockchain in order to enrich their portfolio of products. A number of researchers and practitioners speculate that the blockchain technology can change the way we see a number of online applications today. Although it is still early to tell for sure, it is expected that the blockchain will stimulate considerable changes to a large number of products and will positively impact the digital experience of many individuals around the globe. In this tutorial, we overview, detail, and analyze the security provisions of Bitcoin and its underlying blockchain-effectively capturing recently reported attacks and threats in the system. Our contributions go beyond the mere analysis of reported vulnerabilities of Bitcoin; namely, we describe and evaluate a number of countermeasures to deter threats on the system-some of which have already been incorporated in the system. Recall that Bitcoin has been forked multiple times in order to fine-tune the consensus (i.e., the block generation time and the hash function), and the network parameters (e.g., the size of blocks). As such, the results reported in this tutorial are not only restricted to Bitcoin, but equally apply to a number of "altcoins" which are basically clones/forks of the Bitcoin source code. Given the increasing number of alternative blockchain proposals, this tutorial extracts the basic security lessons learnt from the Bitcoin system with the aim to foster better designs and analysis of next-generation secure blockchain currencies and technologies.

The HTTPS ecosystem, including the SSL/TLS protocol, the X.509 public-key infrastructure, and their cryptographic libraries, is the standardized foundation of Internet Security. Despite 20 years of progress and extensions, however, its practical security remains controversial, as witnessed by recent efforts to improve its design and implementations, as well as recent disclosures of attacks against its deployments. The Everest project is a collaboration between Microsoft Research, INRIA, and the community at large that aims at modelling, programming, and verifying the main HTTPS components with strong machine-checked security guarantees, down to core system and cryptographic assumptions. Although HTTPS involves a relatively small amount of code, it requires efficient low-level programming and intricate proofs of functional correctness and security. To this end, we are also improving our verifications tools (F*, Dafny, Lean, Z3) and developing new ones. In my talk, I will present our project, review our experience with miTLS, a verified reference implementation of TLS coded in F*, and describe current work towards verified, secure, efficient HTTPS.

Customer Edge Switching (CES) is an experimental Internet architecture that provides reliable and resilient multi-domain communications. It provides resilience against security threats because domains negotiate inbound and outbound policies before admitting new traffic. As CES and its signalling protocols are being prototyped, there is a need for independent testing of the CES architecture. Hence, our research goal is to develop an automated test framework that CES protocol designers and early adopters can use to improve the architecture. The test framework includes security, functional, and performance tests. Using the Robot Framework and STRIDE analysis, in this paper we present this automated security test framework. By evaluating sample test scenarios, we show that the Robot Framework and our CES test suite have provided productive discussions about this new architecture, in addition to serving as clear, easy-to-read documentation. Our research also confirms that test automation can be useful to improve new protocol architectures and validate their implementation.

Utility networks are part of every nation's critical infrastructure, and their protection is now seen as a high priority objective. In this paper, we propose a threat awareness architecture for critical infrastructures, which we believe will raise security awareness and increase resilience in utility networks. We first describe an investigation of trends and threats that may impose security risks in utility networks. This was performed on the basis of a viewpoint approach that is capable of identifying technical and non-technical issues (e.g., behaviour of humans). The result of our analysis indicated that utility networks are affected strongly by technological trends, but that humans comprise an important threat to them. This provided evidence and confirmed that the protection of utility networks is a multi-variable problem, and thus, requires the examination of information stemming from various viewpoints of a network. In order to accomplish our objective, we propose a systematic threat awareness architecture in the context of a resilience strategy, which ultimately aims at providing and maintaining an acceptable level of security and safety in critical infrastructures. As a proof of concept, we demonstrate partially via a case study the application of the proposed threat awareness architecture, where we examine the potential impact of attacks in the context of social engineering in a European utility company.

In this paper, we introduce an optical network with cross-layer security, which can enhance security performance. In the transmitter, the user's data is encrypted at first. After that, based on optical encoding, physical layer encryption is implemented. In the receiver, after the corresponding optical decoding process, decryption algorithm is used to restore user's data. In this paper, the security performance has been evaluated quantitatively.

The serializability of transactions is the most important property that ensure correct processing to transactions. In case of concurrent access to the same data by several transactions, or in case of dependency relationships between running sub transactions. But some transactions has been marked as malicious and they compromise the serialization of running system. For that purpose, we propose an intrusion tolerant scheme to ensure the continuity of the running transactions. A transaction dependency graph is also used by the CDC to make decisions concerning the set of data and transactions that are threatened by a malicious activity. We will give explanations about how to use the proposed scheme to illustrate its behavior and efficiency against a compromised transaction-based in a cloud of databases environment. Several issues should be considered when dealing with the processing of a set of interleaved transactions in a transaction based environment. In most cases, these issues are due to the concurrent access to the same data by several transactions or the dependency relationship between running transactions. The serializability may be affected if a transaction that belongs to the processing node is compromised.

Information Centric Networking (ICN) paradigms nicely fit the world of wireless sensors, whose devices have tight constraints. In this poster, we compare two alternative designs for secure association of new IoT devices in existing ICN deployments, which are based on asymmetric and symmetric cryptography respectively. While the security properties of both approaches are equivalent, an interesting trade-off arises between properties of the protocol vs properties of its implementation in current IoT boards. Indeed, while the asymmetric-keys based approach incurs a lower traffic overhead (of about 30%), we find that its implementation is significantly more energy- and time-consuming due to the cost of cryptographic operations (it requires up to 41x more energy and 8x more time).