Biblio

This paper proposes the Digital Public Service Innovation Framework that extends the "standard" provision of digital public services according to the emerging, enhanced, transactional and connected stages underpinning the United Nations Global e-Government Survey, with seven example "innovations" in digital public service delivery – transparent, participatory, anticipatory, personalized, co-created, context-aware and context-smart. Unlike the "standard" provisions, innovations in digital public service delivery are open-ended – new forms may continuously emerge in response to new policy demands and technological progress, and are non-linear – one innovation may or may not depend on others. The framework builds on the foundations of public sector innovation and Digital Government Evolution model. In line with the latter, the paper equips each innovation with sharp logical characterization, body of research literature and real-life cases from around the world to simultaneously serve the illustration and validation goals. The paper also identifies some policy implications of the framework, covering a broad range of issues from infrastructure, capacity, eco-system and partnerships, to inclusion, value, channels, security, privacy and authentication.

Formal specification is a vital ingredient to scalable verification of software systems. In the case of efficient implementations of concurrent objects like atomic registers, queues, and locks, symbolic formal representations of their abstract data types (ADTs) enable efficient modular reasoning, decoupling clients from implementations. Writing adequate formal specifications, however, is a complex task requiring rare expertise. In practice, programmers write reference implementations as informal specifications. In this work we demonstrate that effective symbolic ADT representations can be automatically generated from the executions of reference implementations. Our approach exploits two key features of naturally-occurring ADTs: violations can be decomposed into a small set of representative patterns, and these patterns manifest in executions with few operations. By identifying certain algebraic properties of naturally-occurring ADTs, and exhaustively sampling executions up to a small number of operations, we generate concise symbolic ADT representations which are complete in practice, enabling the application of efficient symbolic verification algorithms without the burden of manual specification. Furthermore, the concise ADT violation patterns we generate are human-readable, and can serve as useful, formal documentation.

To prevent unauthorized parties from accessing data stored on their smartphones, users have the option of enabling a "lock screen" that requires a secret code (e.g., PIN, drawing a pattern, or biometric) to gain access to their devices. We present a detailed analysis of the smartphone locking mechanisms currently available to billions of smartphone users worldwide. Through a month-long field study, we logged events from a panel of users with instrumented smartphones (N=134). We are able to show how existing lock screen mechanisms provide users with distinct tradeoffs between usability (unlocking speed vs. unlocking frequency) and security. We find that PIN users take longer to enter their codes, but commit fewer errors than pattern users, who unlock more frequently and are very prone to errors. Overall, PIN and pattern users spent the same amount of time unlocking their devices on average. Additionally, unlock performance seemed unaffected for users enabling the stealth mode for patterns. Based on our results, we identify areas where device locking mechanisms can be improved to result in fewer human errors – increasing usability – while also maintaining security.

When a group of individuals and organizations wish to compute a stable matching–-for example, when medical students are matched to medical residency programs–-they often outsource the computation to a trusted arbiter in order to preserve the privacy of participants' preferences. Secure multi-party computation offers the possibility of private matching processes that do not rely on any common trusted third party. However, stable matching algorithms have previously been considered infeasible for execution in a secure multi-party context on non-trivial inputs because they are computationally intensive and involve complex data-dependent memory access patterns. We adapt the classic Gale-Shapley algorithm for use in such a context, and show experimentally that our modifications yield a lower asymptotic complexity and more than an order of magnitude in practical cost improvement over previous techniques. Our main improvements stem from designing new oblivious data structures that exploit the properties of the matching algorithms. We apply a similar strategy to scale the Roth-Peranson instability chaining algorithm, currently in use by the National Resident Matching Program. The resulting protocol is efficient enough to be useful at the scale required for matching medical residents nationwide, taking just over 18 hours to complete an execution simulating the 2016 national resident match with more than 35,000 participants and 30,000 residency slots.

In most adaptive video streaming systems adaptation decisions rely solely on the available network resources. As the content of a video has a large influence on the perception of quality our belief is that this is not sufficient. Thus, we have proposed a support service for content-aware video adaptation on mobile devices: Video Adaptation Service (VAS). Based on the content of a streamed video, the adaptation process is improved by setting a target quality level for a session based on an objective video quality metric. In this work, we demonstrate VAS and its advantages of a reduced data traffic by only streaming the lowest video representation which is necessary to reach a desired quality. By leveraging the content properties of a video stream, the system is able to keep a stable video quality and at the same time reduce the network load.

The purpose of this research is to propose architecture-driven, penetration testing equipped with a software reverse and forward engineering process. Although the importance of architectural risk analysis has been emphasized in software security, no methodology is shown to answer how to discover the architecture and abuse cases of a given insecure legacy system and how to modernize it to a secure target system. For this purpose, we propose an architecture-driven penetration testing methodology: 4+1 architectural views of the given insecure legacy system, documented to discover program paths for vulnerabilities through a reverse engineering process. Then, vulnerabilities are identified by using the discovered architecture abuse cases and countermeasures are proposed on identified vulnerabilities. As a case study, a telecommunication company's Identity Access Management (IAM) system is used for discovering its software architecture, identifying the vulnerabilities of its architecture, and providing possible countermeasures. Our empirical results show that functional suggestions would be relatively easier to follow up and less time-consuming work to fix; however, architectural suggestions would be more complicated to follow up, even though it would guarantee better security and take full advantage of OAuth 2.0 supporting communities.

In recent years, prodigious explosion of social network services may trigger new business models. However, it has negative aspects such as personal information spill or spamming, as well. Amongst conventional spam detection approaches, the studies which are based on vertex degrees or Local Clustering Coefficient have been caused false positive results so that normal vertices can be specified as spammers. In this paper, we propose a novel approach by employing the circuit structure in the social networks, which demonstrates the advantages of our work through the experiment.

Emergency evacuations during disasters minimize loss of lives and injuries. It is not surprising that emergency evacuation preparedness is mandatory for organizations in many jurisdictions. In the case of corporations, this requirement translates to considerable expenses, consisting of construction costs, equipment, recruitment, retention and training. In addition, required regular evacuation drills cause recurring expenses and loss of productivity. Any automation to assist in these drills and in actual evacuations can mean savings of costs, time and lives. Evacuation assistance systems rely on attendance systems that often fall short in accuracy, particularly in environments with lot of "non-swipers" (customers, visitors, etc.,). A critical question to answer in the case of an emergency is "How many people are still in the building?". This number is calculated by comparing the number of people gathered at assembly point to the last known number of people inside the building. An IoT based system can enhance the answer to that question by providing the number of people in the building, provide their last known locations in an automated fashion and even automate the reconciliation process. Our proposed system detects the people in the building automatically using multiple channels such as WiFi and motion detection. Such a system needs the ability to link specific identifiers to persons reliably. In this paper we present our statistics and heuristics based solutions for linking detected identifiers as belonging to an actual persons in a privacy preserving manner using IoT technologies.

In this paper we describe and share with the research community, a significant smartphone dataset obtained from an ongoing long-term data collection experiment. The dataset currently contains 10 billion data records from 30 users collected over a period of 1.6 years and an additional 20 users for 6 months (totaling 50 active users currently participating in the experiment). The experiment involves two smartphone agents: SherLock and Moriarty. SherLock collects a wide variety of software and sensor data at a high sample rate. Moriarty perpetrates various attacks on the user and logs its activities, thus providing labels for the SherLock dataset. The primary purpose of the dataset is to help security professionals and academic researchers in developing innovative methods of implicitly detecting malicious behavior in smartphones. Specifically, from data obtainable without superuser (root) privileges. To demonstrate possible uses of the dataset, we perform a basic malware analysis and evaluate a method of continuous user authentication.

In this paper we provide a framework to analyze the effect of uniform sampling on graph optimization problems. Interestingly, we apply this framework to a general class of graph optimization problems that we call heavy subgraph problems, and show that uniform sampling preserves a 1-ε approximate solution to these problems. This class contains many interesting problems such as densest subgraph, directed densest subgraph, densest bipartite subgraph, d-max cut, and d-sum-max clustering. As an immediate impact of this result, one can use uniform sampling to solve these problems in streaming, turnstile or Map-Reduce settings. Indeed, our results by characterizing heavy subgraph problems address Open Problem 13 at the IITK Workshop on Algorithms for Data Streams in 2006 regarding the effects of subsampling, in the context of graph streams. Recently Bhattacharya et al. in STOC 2015 provide the first one pass algorithm for the densest subgraph problem in the streaming model with additions and deletions to its edges, i.e., for dynamic graph streams. They present a (0.5-ε)-approximation algorithm using \textasciitildeO(n) space, where factors of ε and log(n) are suppressed in the \textasciitildeO notation. In this paper we improve the (0.5-ε)-approximation algorithm of Bhattacharya et al. by providing a (1-ε)-approximation algorithm using \textasciitildeO(n) space.

In a secret sharing scheme a dealer shares a secret s among n parties such that an adversary corrupting up to t parties does not learn s, while any t+1 parties can efficiently recover s. Over a long period of time all parties may be corrupted thus violating the threshold, which is accounted for in Proactive Secret Sharing (PSS). PSS schemes periodically rerandomize (refresh) the shares of the secret and invalidate old ones. PSS retains confidentiality even when all parties are corrupted over the lifetime of the secret, but no more than t during a certain window of time, called the refresh period. Existing PSS schemes only guarantee secrecy in the presence of an honest majority with less than n2 total corruptions during a refresh period; an adversary corrupting a single additional party, even if only passively, obtains the secret. This work is the first feasibility result demonstrating PSS tolerating a dishonest majority, it introduces the first PSS scheme secure against t passive adversaries without recovery of lost shares, it can also recover from honest faulty parties losing their shares, and when tolerating e faults the scheme tolerates t passive corruptions. A non-robust version of the scheme can tolerate t active adversaries, and mixed adversaries that control a combination of passively and actively corrupted parties that are a majority, but where less than n/2-e of such corruptions are active. We achieve these high thresholds with O(n4) communication when sharing a single secret, and O(n3) communication when sharing multiple secrets in batches.

Critical infrastructure such as the power grid has become increasingly complex. The addition of computing elements to traditional physical components increases complexity and hampers insight into how elements in the system interact with each other. The result is an infrastructure where operational mistakes, some of which cannot be distinguished from attacks, are more difficult to prevent and have greater potential impact, such as leaking sensitive information to the operator or attacker. In this paper, we present CPAC, a cyber-physical access control solution to manage complexity and mitigate threats in cyber-physical environments, with a focus on the electrical smart grid. CPAC uses information flow analysis based on mathematical models of the physical grid to generate policies enforced through verifiable logic. At the device side, CPAC combines symbolic execution with lightweight dynamic execution monitoring to allow non-intrusive taint analysis on programmable logic controllers in realtime. These components work together to provide a realtime view of all system elements, and allow for more robust and finer-grained protections than any previous solution to securing the grid. We implement a prototype of CPAC using Bachmann PLCs and evaluate several real-world incidents that demonstrate its scalability and effectiveness. The policy checking for a nation-wide grid is less than 150 ms, faster than existing solutions. We additionally show that CPAC can analyze potential component failures for arbitrary component failures, far beyond the capabilities of currently deployed systems. CPAC thus provides a solution to secure the modern smart grid from operator mistakes or insider attacks, maintain operational privacy, and support N - x contingencies.

We tackle the problem of automated exploit generation for web applications. In this regard, we present an approach that significantly improves the state-of-art in web injection vulnerability identification and exploit generation. Our approach for exploit generation tackles various challenges associated with typical web application characteristics: their multi-module nature, interposed user input, and multi-tier architectures using a database backend. Our approach develops precise models of application workflows, database schemas, and native functions to achieve high quality exploit generation. We implemented our approach in a tool called Chainsaw. Chainsaw was used to analyze 9 open source applications and generated over 199 first- and second-order injection exploits combined, significantly outperforming several related approaches.

Keys for symmetric cryptography are usually stored in RAM and therefore susceptible to various attacks, ranging from simple buffer overflows to leaks via cold boot, DMA or side channels. A common approach to mitigate such attacks is to move the keys to an external cryptographic token. For low-throughput applications like asymmetric signature generation, the performance of these tokens is sufficient. For symmetric, data-intensive use cases, like disk encryption on behalf of the host, the connecting interface to the token often is a serious bottleneck. In order to overcome this problem, we present CoKey, a novel concept for partially moving symmetric cryptography out of the host into a trusted detachable token. CoKey combines keys from both entities and securely encrypts initialization vectors on the token which are then used in the cryptographic operations on the host. This forces host and token to cooperate during the whole encryption and decryption process. Our concept strongly and efficiently binds encrypted data on the host to the specific token used for their encryption, while still allowing for fast operation. We implemented the concept using Linux hosts and the USB armory, a USB thumb drive sized ARM computer, as detachable crypto token. Our detailed performance evaluation shows that our prototype is easily fast enough even for data-intensive and performance-critical use cases like full disk encryption, thus effectively improving security for symmetric cryptography in a usable way.

In today's enterprise networks, there are many ways for a determined attacker to obtain a foothold, bypass current protection technologies, and attack the intended target. Over several years we have developed the Self-shielding Dynamic Network Architecture (SDNA) technology, which prevents an attacker from targeting, entering, or spreading through an enterprise network by adding dynamics that present a changing view of the network over space and time. SDNA was developed with the support of government sponsored research and development and corporate internal resources. The SDNA technology was purchased by Cryptonite, LLC in 2015 and has been developed into a robust product offering called Cryptonite NXT. In this paper, we describe the journey and lessons learned along the course of feasibility demonstration, technology development, security testing, productization, and deployment in a production network.

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.

Semi-autonomous driver assists are already widely deployed and fully autonomous cars are progressively leaving the realm of laboratories. This evolution coexists with a progressive connectivity and cooperation, creating important safety and security challenges, the latter ranging from casual hackers to highly-skilled attackers, requiring a holistic analysis, under the perspective of fully-fledged ecosystems of autonomous and cooperative vehicles. This position paper attempts at contributing to a better understanding of the global threat plane and the specific threat vectors designers should be attentive to. We survey paradigms and mechanisms that may be used to overcome or at least mitigate the potential risks that may arise through the several threat vectors analyzed.

Internet Service Providers (ISPs) use the Border Gateway Protocol (BGP) to announce and exchange routes for de- livering packets through the internet. ISPs must carefully configure their BGP routers to ensure traffic is routed reli- ably and securely. Correctly configuring BGP routers has proven challenging in practice, and misconfiguration has led to worldwide outages and traffic hijacks. This paper presents Bagpipe, a system that enables ISPs to declaratively express BGP policies and that automatically verifies that router configurations implement such policies. The novel initial network reduction soundly reduces policy verification to a search for counterexamples in a finite space. An SMT-based symbolic execution engine performs this search efficiently. Bagpipe reduces the size of its search space using predicate abstraction and parallelizes its search using symbolic variable hoisting. Bagpipe's policy specification language is expressive: we expressed policies inferred from real AS configurations, policies from the literature, and policies for 10 Juniper TechLibrary configuration scenarios. Bagpipe is efficient: we ran it on three ASes with a total of over 240,000 lines of Cisco and Juniper BGP configuration. Bagpipe is effective: it revealed 19 policy violations without issuing any false positives.

Role-based Access Control (RBAC) is a popular solution for implementing information security however there is no pervasive methodology used to produce scalable access control systems for large organizations with hundreds or thousands of employees. As a result ten engineers will likely arrive at ten different solutions to the same problem where there is no right or wrong answer but there is both an immediate and long term cost. Moreover, they would have difficulty communicating the important aspects of their design implementations to each other. This is an interesting deficiency because despite their diversity, large organizations are built upon two key concepts, roles and responsibilities, where a role like Departmental Chair is identified and assigned responsibilities. In this paper, our objective is to introduce ORGODEX, a new model and practical methodology for engineering scalable RBAC systems in large organizations where employees require access to information on a need to know basis. First, we motivate the requirement for a new RBAC dichotomy, distinguishing between roles and responsibilities. Next, we introduce our new model for describing and reasoning about RBAC systems with this new dichotomy. Finally, we produce a new iterative methodology for engineering scalable access control systems.

One of the main concerns for smartphone users is the quality of apps they download. Before installing any app from the market, users first check its rating and reviews. However, these ratings are not computed by experts and most times are not associated with malicious behavior. In this work, we present an IDS/rating system based on a game theoretic model with crowdsourcing. Our results show that, with minor control over the error in categorizing users and the fraction of experts in the crowd, our system provides proper ratings while flagging all malicious apps.

Energy management systems (EMS) are used to control energy usage in buildings and campuses, by employing technologies such as supervisory control and data acquisition (SCADA) and building management systems (BMS), in order to provide reliable energy supply and maximise user comfort while minimising energy usage. Historically, EMS systems were installed when potential security threats were only physical. Nowadays, EMS systems are connected to the building network and as a result directly to the outside world. This extends the attack surface to potential sophisticated cyber-attacks, which adversely impact EMS operation, resulting in service interruption and downstream financial implications. Currently, the security systems that detect attacks operate independently to those which deploy resiliency policies and use very basic methods. We propose a novel EMS cyber-physical-security framework that executes a resilient policy whenever an attack is detected using security analytics. In this framework, both the resilient policy and the security analytics are driven by EMS data, where the physical correlations between the data-points are identified to detect outliers and then the control loop is closed using an estimated value in place of the outlier. The framework has been tested using a reduced order model of a real EMS site.

Head portraits are popular in traditional painting. Automating portrait painting is challenging as the human visual system is sensitive to the slightest irregularities in human faces. Applying generic painting techniques often deforms facial structures. On the other hand portrait painting techniques are mainly designed for the graphite style and/or are based on image analogies; an example painting as well as its original unpainted version are required. This limits their domain of applicability. We present a new technique for transferring the painting from a head portrait onto another. Unlike previous work our technique only requires the example painting and is not restricted to a specific style. We impose novel spatial constraints by locally transferring the color distributions of the example painting. This better captures the painting texture and maintains the integrity of facial structures. We generate a solution through Convolutional Neural Networks and we present an extension to video. Here motion is exploited in a way to reduce temporal inconsistencies and the shower-door effect. Our approach transfers the painting style while maintaining the input photograph identity. In addition it significantly reduces facial deformations over state of the art.

This paper presents a multi-year undergraduate computing capstone project that holistically contributes to the development of cybersecurity knowledge and skills in non-computing high school and college students. We describe the student-built Vulnerable Web Server application, which is a system that packages instructional materials and pre-built virtual machines to provide lessons on cybersecurity to non-technical students. The Vulnerable Web Server learning materials have been piloted at several high schools and are now integrated into multiple security lessons in an intermediate, general education information technology course at the United States Military Academy. Our paper interweaves a description of the Vulnerable Web Server materials with the senior capstone design process that allowed it to be built by undergraduate information technology and computer science students, resulting in a valuable capstone learning experience. Throughout the paper, a call is made for greater emphasis on educating the non-technical user.

Intel SGX is the latest processor architecture promising secure code execution despite large, complex and hence potentially vulnerable legacy operating systems (OSs). However, two recent works identified vulnerabilities that allow an untrusted management OS to extract secret information from Intel SGX's enclaves, and to violate their integrity by exploiting concurrency bugs. In this work, we re-investigate delayed preemption (DP) in the context of Intel SGX. DP is a mechanism originally proposed for L4-family microkernels as disable-interrupt replacement. Recapitulating earlier results on language-based information-flow security, we illustrate the construction of leakage-free code for enclaves. However, as long as adversaries have fine-grained control over preemption timing, these solutions are impractical from a performance/complexity perspective. To overcome this, we resort to delayed preemption, and sketch a software implementation for hypervisors providing enclaves as well as a hardware extension for systems like SGX. Finally, we illustrate how static analyses for SGX may be extended to check confidentiality of preemption-delaying programs.