Usually, a proof of a theorem contains more knowledge than the mere fact that the theorem is true. For instance, to prove that a graph is Hamiltonian it suffices to exhibit a Hamiltonian tour in it; however, this seems to contain more knowledge than the single bit Hamiltonian/non-Hamiltonian.In this paper a computational complexity theory of the “knowledge” contained in a proof is developed. Zero-knowledge proofs are defined as those proofs that convey no additional knowledge other than the correctness of the proposition in question. Examples of zero-knowledge proof systems are given for the languages of quadratic residuosity and 'quadratic nonresiduosity. These are the first examples of zero-knowledge proofs for languages not known to be efficiently recognizable.

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The knowledge complexity of interactive proof-systems

[서평]「Component Software」 - Beyond Object-Oriented Programming -

Stephen J. Hartley Oxford University Press, New York, 1998, 260 pp. ISBN 0-19-511315-2, $45.00 Concurrent Programming  is a thorough treatment of Java multi-threaded programming for both a stand-alone and distributed environment. Designed mostly for students in concurrent or parallel programming classes, the text is also an excellent reference for the practicing professional developing multi-threaded programs or applets. Hartley first provides a complete explanation of the features of Java necessary to write concurrent programs, including topics such as exception handling, interfaces, and packages. He then gives the reader a solid background to write multi-threaded programs and also presents the problems introduced when writing concurrent programs—namely race conditions, mutual exclusion, and deadlock. Hartley also provides several software solutions that do not require the use of common process and thread mechanisms. Once the groundwork is laid for writing concurrent programs, Hartley then takes a different approach than most Java references. Rather than presenting how Java handles mutual exclusion with the  synchronized  keyword (although it is covered later), he first looks at semaphore-based solutions to classic concurrent problems such as bounded-buffer, readers-writers, and the dining philosophers. Hartley also uses the same approach to develop Java classes for monitors and message passing. This unique approach to introducing concurrency allows the readers to both understand how Java threads are synchronized and how the basic synchronization mechanism can be used to construct more abstract tools such as semaphores. If there is a shortcoming with the text it is with the lack of sufficient coverage of remote method invocation (RMI), although there is a section covering RMI. This is quite understandable as RMI is a fairly recent phenomenon with the Java community. Also, the classes that Hartley provides could easily implement RMI rather than sockets to handle communication. The strengths of the book include its ease in reading, several examples at the end of chapters, a package similar to Xtango that provides algorithm animation, and a supportive web site by the author (see  www.mcs.drexel.edu/~shartley/ConcProgJava/index.html ) including compressed source code. As Java becomes more dominant on the server side of multi-tier applications, writing thread-safe concurrent applications becomes even more important.  Concurrent Programming  is a strong step towards teaching students and professionals such skills. Greg Gagne, Westminster College of Salt Lake City Salt Lake City, Utah

Distributed Computing: Fundamentals, Simulations and Advanced Topics

Anomaly detection is an important problem that has been well-studied within diverse research areas and application domains. The aim of this survey is two-fold, firstly we present a structured and comprehensive overview of research methods in deep learning-based anomaly detection. Furthermore, we review the adoption of these methods for anomaly across various application domains and assess their effectiveness. We have grouped state-of-the-art research techniques into different categories based on the underlying assumptions and approach adopted. Within each category we outline the basic anomaly detection technique, along with its variants and present key assumptions, to differentiate between normal and anomalous behavior. For each category, we present we also present the advantages and limitations and discuss the computational complexity of the techniques in real application domains. Finally, we outline open issues in research and challenges faced while adopting these techniques.

Deep Learning for Anomaly Detection: A Survey.

Software testing is all too often simply a bug hunt rather than a wellconsidered exercise in ensuring quality. A more methodical approach than a simple cycle of system-level test-fail-patch-test will be required to deploy safe autonomous vehicles at scale. The ISO 26262 development V process sets up a framework that ties each type of testing to a corresponding design or requirement document, but presents challenges when adapted to deal with the sorts of novel testing problems that face autonomous vehicles. This paper identifies five major challenge areas in testing according to the V model for autonomous vehicles: driver out of the loop, complex requirements, non-deterministic algorithms, inductive learning algorithms, and failoperational systems. General solution approaches that seem promising across these different challenge areas include: phased deployment using successively relaxed operational scenarios, use of a monitor/actuator pair architecture to separate the most complex autonomy functions from simpler safety functions, and fault injection as a way to perform more efficient edge case testing. While significant challenges remain in safety-certifying the type of algorithms that provide high-level autonomy themselves, it seems within reach to instead architect the system and its accompanying design process to be able to employ existing software safety approaches.

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Challenges in Autonomous Vehicle Testing and Validation

Event logging is a key source of information on a system state. Reading logs provides insights on its activity, assess its correct state and allows to diagnose problems. However, reading does not scale: with the number of machines increasingly rising, and the complexification of systems, the task of auditing systems' health based on logfiles is becoming overwhelming for system administrators. This observation led to many proposals automating the processing of logs. However, most of these proposal still require some human intervention, for instance by tagging logs, parsing the source files generating the logs, etc.In this work, we target minimal human intervention for logfile processing and propose a new approach that considers logs as regular text (as opposed to related works that seek to exploit at best the little structure imposed by log formatting). This approach allows to leverage modern techniques from natural language processing. More specifically, we first apply a word embedding technique based on Google's word2vec algorithm: logfiles' words are mapped to a high dimensional metric space, that we then exploit as a feature space using standard classifiers. The resulting pipeline is very generic, computationally efficient, and requires very little intervention.We validate our approach by seeking stress patterns on an experimental platform. Results show a strong predictive performance (&#x2248; 90% accuracy) using three out-of-the-box classifiers.

/pdf/experience-report-log-mining-using-natural-language-24ua065i9p.pdf

Experience Report: Log Mining Using Natural Language Processing and Application to Anomaly Detection

Safety-critical systems with decisional abilities, such as autonomous robots, are about to enter our everyday life. Nevertheless, confidence in their behavior is still limited, particularly regarding safety. Considering the variety of hazards that can affect these systems, many techniques might be used to increase their safety. Among them, active safety monitors are a means to maintain the system safety in spite of faults or adverse situations. The specification of the safety rules implemented in such devices is of crucial importance, but has been hardly explored so far. In this paper, we propose a complete framework for the generation of these safety rules based on the concept of safety margin. The approach starts from a hazard analysis, and uses formal verification techniques to automatically synthesize the safety rules. It has been successfully applied to an industrial use case, a mobile manipulator robot for co-working.

/pdf/smof-a-safety-monitoring-framework-for-autonomous-systems-3ypfzorlcu.pdf

SMOF: A Safety Monitoring Framework for Autonomous Systems

When integrating mixed critical systems on a multi/many-core, one challenge is to ensure predictability for high criticality tasks and an increased utilization for low criticality tasks In this paper, we address this problem when several high criticality tasks with different deadlines, periods and offsets are concurrently executed on the system We propose a distributed run-time WCET controller that works as follows: (1) locally, each critical task regularly checks if the interferences due to the low criticality tasks can be tolerated, otherwise it decides their suspension; (2) globally, a master suspends and restarts the low criticality tasks based on the received requests from the critical tasks Our approach has been implemented as a software controller on a real multi-core COTS system with significant gains

/pdf/distributed-run-time-wcet-controller-for-concurrent-critical-2s1awh87ud.pdf

Distributed run-time WCET controller for concurrent critical tasks in mixed-critical systems

Although multi/many-core platforms enable the parallel execution of tasks, the sharing of resources may lead to long WCETs that fail to meet the real-time constraints of the system. Then, a safe solution is the execution of the most critical tasks in isolation followed by the execution of the remaining tasks. To improve the system performance, we propose an approach where a critical task can run in parallel with less critical tasks, as long as the real-time constraints are met. When no further interferences can be tolerated, the proposed run-time control suspends the low critical tasks until the termination of the critical task. In this paper, we describe the design and prove the correctness of our approach. To do so, a graph grammar is defined to formally model the critical task as a set of control flow graphs on which a safe partial WCET analysis is applied and used at run-time to control the safe execution of the critical task.

/pdf/run-time-control-to-increase-task-parallelism-in-mixed-2a1s646zqt.pdf

Run-Time Control to Increase Task Parallelism In Mixed-Critical Systems

A secure location-based service requires that a mobile user certifies his position before gaining access to a resource. Currently, most of the existing solutions addressing this issue assume a trusted third party that can vouch for the position claimed by a user. However, as computation and communication capacities become ubiquitous with the large scale adoption of smartphones by individuals, we propose to leverage on these resources to solve this issue in a collaborative and private manner. More precisely, we introduce PROPS, for PRivacy-preserving lOcation Proof System, which allows users to generate proofs of location in a private and distributed way using neighboring nodes as witnesses. PROPS provides security properties such as unforgeability and non-transferability of the proofs, as well as resistance to classical localization attacks.

/pdf/props-a-privacy-preserving-location-proof-system-2gi8u64n9c.pdf

Matthieu Roy

Papers

Experience Report: Log Mining Using Natural Language Processing and Application to Anomaly Detection

SMOF: A Safety Monitoring Framework for Autonomous Systems

Distributed run-time WCET controller for concurrent critical tasks in mixed-critical systems

Run-Time Control to Increase Task Parallelism In Mixed-Critical Systems

PROPS: A PRivacy-Preserving Location Proof System