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Terrorist fraud is an attack against distance bounding protocols, whereby a malicious prover allows an adversary to authenticate on their behalf without revealing their secret key. In this paper, we propose new attack strategies that lead to successful terrorist frauds on proven-secure protocols.

Most research modelling Bitcoin-style decentralised consensus protocols has assumed profit-motivated participants. Complementary to this analysis, we revisit the notion of attackers with an extrinsic motivation to disrupt the consensus process (Goldfinger attacks). We outline several routes for obtaining a majority of decision-making power in the consensus protocol (a hostile takeover). Our analysis suggests several fundamental differences between proof-of-work and proof-of-stake systems in the face of such an adversary.

Part 8: Pattern Recognition and Image Processing; International audience; Paper-based documents are important and still widely used in government agencies and private entities as some documents cannot be replaced by electronic documents. These include loan agreements, dispatch or contracts, household registrations and passports. They must be paper-based. Paper-based documents can be easily forged with a printer and a scanner, and imaging software can easily edit them. This paper presents a paper-based document authentication by applying a digital signature and HC2D barcode to verify the integrity of the text message and the sender of the document. This is useful both for a quick inspection of documents with large quantities and monitoring that may help prevent fraud and forgery which may have occurred.

This paper presents the results from a tertiary entrance test that was delivered to two groups of candidates, one as a paper based test and the other as a computer based test. Item level differential reveals a pattern that appears related to item type: questions based on diagrammatic stimulus show a pattern of increased difficulty when delivered on computer. Differential in performance was not present in other sections of the test and it would appear unlikely to be explained by demographic differences between the groups. It is suggested this differential is due to the inability of the candidates to freely annotate on the stimulus when delivered on computer screen. More work needs to be done on considering the role of annotation as a problem solving strategy in high-stakes testing, in particular with certain kinds of stimulus, such as diagrams.

Consumers are often willing to contribute their personal data for analytics projects that may create new insights into societal problems. However, consumers also have justified privacy concerns about the release of their data.

Over several decades, a large body of research has been established that focuses on Pen-and-Paper Computing. This chapter reviews previous work of the field – both from a technological and interface perspective – and discusses future directions of research and development.

Personal Digital Assistants (PDAs) are a viable technology for providing access to Electronic Medical Records at the point-of-care. However, acceptance of this technology by clinicians will depend on how easy they can make the transition from the system they normally use to a PDA-based system. Since many hospitals are still using paper-based patient record systems this study intends to provide some insight on the aspects that need to be considered in the transition from a paper-based system to a PDA-based system. The study compares the interaction of nurses with PDA-based and paper-based nursing documentation systems in terms of performance and subjective satisfaction. Twenty staff nurses from a metropolitan hospital performed twelve tasks on each system. The study supports the conclusion that a PDA-based nursing documentation system can be superior to a paper-based system in term of performance for tasks that don't required writing notes. Nurses were significantly more satisfied with the PDA-based system than with the paper-based system with every interaction and system aspect evaluated on the study. In general the results of the study provide hard evidence to predict an easy transition for nurses from a paper-based system to a PDA-based system nursing documentation system.

Identifying the natural gestures for a tabletop application is one of the most challenging tasks developers must accomplish in order to achieve a good system user interface. This problem is even more difficult in a collaborative environment. Cooperative Gestures allow richer interaction and must be evaluated when designing a new multi-user tabletop interface. In this paper we present the use of paper prototyping to analyze user interaction on a tabletop collaborative game application. Our results show that it is possible to extract natural gestures for an application using this technique, regardless of some limitations.

This paper proposes a novel system which automatically extracts the intended items to buy from a hand written shopping list. This intelligent shopping list relies on an ontology of the products which is provided by the shopping mall. In our scenario the shopping list is written on digital Anoto paper. After transmitting the hand written strokes to the computer, the list items are recognized by a hand writing recognition system. Next, the recognized text is parsed in order to detect the amount and the desired item. This is then matched to the underlying ontology and the intended order is recognized. Our current prototype works on an ontology of 300 products. In our real-world experiments we asked 20 persons to write shopping lists without any constrains.

In this paper we show how privacy of genomic sequences can be protected while they are analyzed using Hidden Markov Models (HMM), which is commonly done in bioinformatics to detect certain non-beneficial patterns in the genome. Besides offering strong privacy guarantees, our solution also allows protecting the intellectual property of the parties involved, which makes the solution viable for implementation of secure bioinformatics services. In particular, we show how two mutually mistrusting parties can obliviously run the forward algorithm in a setup where one party knows a HMM and another party knows a genomic string; while the parties learn whether the model fits the genome, they neither have to disclose the parameterization of the model nor the sequence to each other. Despite the huge number of arithmetic operations required to solve the problem, we experimentally show that HMMs with sizes of practical importance can obliviously be evaluated using computational resources typically found in medical laboratories. As a central technical contribution, we give improved protocols for secure and numerically stable computations on non-integer values.

This paper introduces the compelled certificate creation attack, in which government agencies may compel a certificate authority to issue false SSL certificates that can be used by intelligence agencies to covertly intercept and hijack individuals' secure Web-based communications.

With tactile paper prototyping user interfaces can be evaluated with blind users in an early design stage. First, we describe two existing paper prototyping methods, visual and haptic paper prototyping, and indicate their limitations for blind users. Subsequently, we present our experiences while preparing, conducting and analysing tests performed using tactile paper prototyping. Based on our experiences, we provide recommendations for this new usability evaluation method.

This paper presents an evaluation framework for analytical methods of integrating eWOM Information. This framework involves a communication model that assumes a set of human subjective probabilities called an belief source and includes two translation processes: (1) encoding the belief source into a representation to communicate with a computer; these encoded messages are called eWOM messages, and (2) in the computer, decoding the eWOM messages to estimate the probabilities in the belief source. The efficiency of reducing the difficulty of describing the belief source and the accuracy of reconstructing the belief source are quantitated using this model. The evaluation processes are illustrated with an analytical method of integrating eWOM messages for probabilistic classification problems.

An increasing number of Internet traders exclusively sell digital products. These digital products can include media files, licenses, services, or subscriptions. We consider the concept of digital provenance in reseller chains. The goal of this work is to provide an honest customer with a guarantee on the origin and ownership history for a digital item even when the reseller they are dealing with is untrusted. We introduce a protocol called the Tagged Transaction protocol which uses a third party called the Tag Generation Centre (TGC) to provide a method for honest customers to check they are purchasing a legitimate item, anonymity for customers and resellers, a method for customers to resell items they have purchased to other customers, and verification of the TGC.

In Role Based Access Control (RBAC) systems, formulating a correct set of roles, assigning appropriate privileges to roles, and assigning roles to users are the fundamental design tasks. Whether these tasks are performed by a human (e.g., system administrator) or by a machine (e.g., expert system), misconfigurations are likely to occur. The misconfigurations could manifest as under-privileges (fewer privileges assigned) or over-privileges (more privileges than necessary). In this paper, we describe an approach based on role mining to detect and correct such misconfigurations. Here, the overlap among the users and privileges of different roles is used to identify possible misconfigurations.

According to the fuzziness of Each index in Test quality evaluation, The entropy value theory of information will be used to test quality evaluation, use The difficulty, degree of differentiate, believe degree, validity and the standard deviation. As the impact of the test quality evaluation index. Establish a comprehensive evaluation index system, Using the information entropy as evaluation index weight coefficient, which can effectively solve the weight distribution difficulties. Weight is an objectivity, This method is a new test quality evaluation method, and connecting with the example of application, The results show that the method was simple, practical and reliable.

Though computing environments are developed very rapidly, people use paper documents as ever. In this paper, we propose the Advanced Paper Document (APD), which expands the function of paper documents, based on the Augmented Desk system. To incorporate physical paper documents with digital documents in a projection display system without being required to use additional sensors, we use a gesture recognition method. The APD has advantages of paper and digital documents, and provides a user with a natural and intuitive environment. As shown by experimental results, the proposed the APD is applicable to provide an interactive computing environment.

We examine the properties and use of paper in everyday settings and discuss the motivation for retaining paper as an information medium. In particular, we consider the use of paper maps and guidebooks by tourists during city visits as an example of a mobile and collaborative environment. We then go on to present recent developments in technologies for digital paper and how they can be used to seamlessly integrate digital and printed information.

This paper concerns blind signature schemes. We focus on two moves constructions, which imply concurrent security. There are known efficient blind signature schemes based on the random oracle model and on the common reference string model. However, constructing two move blind signatures in the standard model is a challenging task, as shown by the impossibility results of Fischlin et al. The recent construction by Garg et al. (Eurocrypt’14) bypasses this result by using complexity leveraging, but it is impractical due to the signature size (\(\approx \) 100 kB). Fuchsbauer et al. (Crypto’15) presented a more practical construction, but with a security argument based on interactive assumptions. We present a blind signature scheme that is two-move, setup-free and comparable in terms of efficiency with the results of Fuchsbauer et al. Its security is based on a knowledge assumption.

Most electronic payment systems for applications, such as eTicketing and eToll, involve a single entity acting as both merchant and bank. In this paper, we propose an efficient privacy-preserving post-payment eCash system suitable for this particular use case that we refer to, afterwards, as private eCash. To this end, we introduce a new partially blind signature scheme based on a recent Algebraic MAC scheme due to Chase et al. Unlike previous constructions, it allows multiple presentations of the same signature in an unlinkable way. Using it, our system is the first versatile private eCash system where users must only hold a sole reusable token (i.e. a reusable coin spendable to a unique merchant). It also enables identity and token revocations as well as flexible payments. Indeed, our payment tokens are updated in a partially blinded way to collect refunds without invading user’s privacy. By implementing it on a Global Platform compliant SIM card, we show its efficiency and suitability for real-world use cases, even for delay-sensitive applications and on constrained devices as a transaction can be performed in only 205 ms.

HCI have long moved beyond the evaluation setting of a single user sitting in front of a single desktop computer, yet many of our fundamentally held viewpoints about evaluation continues to be ruled by outdated biases derived from this legacy. We need to engage with real users in 'Living Laboratories', in which researchers either adopt or create functioning systems that are used in real settings. These new experimental platforms will greatly enable researchers to conduct evaluations that span many users, places, time, location, and social factors in ways that are unimaginable before.

Recently, a number of ID-based authenticated key agreement protocols from bilinear pairings have been proposed. In this paper we present security analysis of four ID-based authenticated key agreement protocols from pairings proposed in [11, 12, 7, 18]. These results demonstrate that no more ID-based authenticated key agreement protocols should be constructed with such ad-hoc methods, i.e, the formal design methodology as in [1, 2, 3, 10] should be employed in future design.

Cooperation between participants is essential to P2P applications' viability. Due to obscure possibility to match peers' needs and supplies in pairs, the widely used pair-wise exchange-based incentive schemes perform poorly. The N-way exchange-based incentive scheme enlarges the matching possibility by introducing n person exchanges. But some old problems remain and some new ones emerge with the N-way design. In this paper we present an enhanced n-way exchange-based incentive scheme for P2P file sharing systems. By distributing extra tasks to all the peers involved in an n-way exchange, the proposed scheme eliminates prohibitive computation and communication cost on the cooperators, resulting in greater efficiency, effectiveness, and security.

There has been considerable interest recently on developing a system to track items like pharmaceutical drugs or food products. Such a system can help prevent counterfeits, aid product recall, and improve general logistics. In this paper, we present such system based on radio frequency identity (RFID) technology. Our solution provides the means of storing the entire movement of the item from original manufacturer to final consumer on the RFID tag itself, and also makes it more difficult to introduce large numbers of counterfeits. The solution also allows the end user to easily verify the authenticity of the item.

A low-rate DoS attack to iterative servers has recently appeared as a new approach for defeating services using rates of traffic that could be adjusted to bypass security detection mechanisms. Although the fundamentals and effectiveness of these kind of attacks are known, it is not clear how to design the attack to achieve specific constraints based on the used rate and the efficiency in denial of service obtained. In this paper, a comprehensive mathematical framework that models the behaviour of the attack is presented. The main contribution of this model is to give a better understanding of the dynamics of these kind of attacks, in order to facilitate the development of detection and defense mechanisms.

Geoinformation systems (GIS) contain information about objects in geographic space; the focus on geographic space [1] determines the scale of spatial objects and processes of interest at a spatial resolution of approximatively 0.1 m to 40.000 km and to changes occurring once a minute to once a million years. Geographic information is a diverse field which includes many special applications, each of which has special requirements, with special kinds of geometry and particular geometric operations.

Software architecture (SA) evaluation is a quality assurance technique that is increasingly attracting significant research and commercial interests. A number of SA evaluation methods have been developed. Most of these methods are scenario-based, which relies on the quality of the scenarios used for the evaluation. Most of the existing techniques for developing scenarios use stakeholders and requirements documents as main sources of collecting scenarios. Recently, architectures of large software systems are usually composed of patterns and styles. One of the purposes of using patterns is to develop systems with predictable quality attributes. Since patterns are documented in a format that requires the inclusion of problem, solution and quality consequences, we observed that scenarios are, though as informal text, pervasive in patterns description, which can be extracted and documented for the SA evaluation. Thus, we claim that the patterns can be another source of collecting quality attributes sensitive scenarios. This position paper presents arguments and examples to support our claim.

Writing on the board is an important part of a lecture. Lecturers’ handwriting is not always perfect. Usually, a lecturer can write slower and more legibly, this will increase understandability but slow down the lecture. In this chapter, we analyze an optimal trade-off between speed and legibility.

Smart mobile devices process and store a vast amount of security- and privacy-sensitive data. To protect this data from malicious applications mobile operating systems, such as Android, adopt fine-grained access control architectures. However, related work has shown that these access control architectures are susceptible to application-layer privilege escalation attacks. Both automated static and dynamic program analysis promise to proactively detect such attacks. Though while state-of-the-art static analysis frameworks cannot adequately address native and highly obfuscated code, dynamic analysis is vulnerable to malicious applications using logic bombs to avoid early detection.

The most common method for a user to gain access to a system, service, or resource is to provide a secret, often a password, that verifies her identity and thus authenticates her. Password-based authentication is considered strong only when the password meets certain length and complexity requirements, or when it is combined with other methods in multi-factor authentication. Unfortunately, many authentication systems do not enforce strong passwords due to a number of limitations; for example, the time taken to enter complex passwords. We present an authentication system that addresses these limitations by prompting a user for credentials once and then storing an authentication ticket in a wearable device that we call Kerberos Bracelet Identification (KBID).

Following the Model-Driven Architecture (MDA),a system description consists of several models,i.e.views of the system.This paper is concerned with formal conformance tests between different models.It stresses the need for formal semantical foundations of all languages that are used to express models.In particular,we classify conformance tests for implementation models

Process and workflow technology have traditionally not allowed for the specification of, nor run-time enforcement of, real-time requirements, despite the fact that time-to-market and other real-time constraints are more stringent than ever. Without specification of timing constraints, process designers cannot effectively reason about real-time constraints on process programs and the efficacy of their process programs in satisfying those constraints. Furthermore, without executable semantics for those timing specifications, such reasoning might not be applicable to the process as actually executed. We seek to support reasoning about the real-time requirements of software processes. In this paper, we describe work in which we have added real-time specifications to a process programming language, and in which we have added deadline timers and task scheduling to enforce the real-time requirements of processes.

The mission of theoretical cryptography is to define and construct provably secure cryptographic protocols and schemes. Without proofs of security, cryptographic constructs offer no guarantees whatsoever and no basis for evaluation and comparison. As most security proofs necessarily come in the form of a reduction between the security claim and an intractability assumption, such proofs are ultimately only as good as the assumptions they are based on. Thus, the complexity implications of every assumption we utilize should be of significant substance, and serve as the yard stick for the value of our proposals. Lately, the field of cryptography has seen a sharp increase in the number of new assumptions that are often complex to define and difficult to interpret. At times, these assumptions are hard to untangle from the constructions which utilize them. We believe that the lack of standards of what is accepted as a reasonable cryptographic assumption can be harmful to the credibility of our field. Therefore, there is a great need for measures according to which we classify and compare assumptions, as to which are safe and which are not. In this paper, we propose such a classification and review recently suggested assumptions in this light. This follows the footsteps of Naor Crypto 2003. Our governing principle is relying on hardness assumptions that are independent of the cryptographic constructions.

The aim of the TACOMA project1 [JvRS95] is to provide middle-ware support for mobile code (or mobile agents, hereafter simply referred to as agents). Our current focus involves issues such as host integrity, agent integrity, management and applicability of this paradigm. The TACOMA system is a mobile agent system which support agents written in a wide variety of languages (such as C, Perl, Python, Scheme, and Tcl). The last publically available prototype supported most flavors of UNIX, and the current implementation has been ported to Win32 and PalmOS.

Up to the twenty-first century, paper is still widely adopted for recording and reading. However, paper-based materials are fully capable of presenting abstract concepts and complicated knowledge with static text and figures. Learners usually need timely and adequate supports when encountering difficulties during learning. With a consideration of applying technologies, the learning tool must have a certain mobility and accessibility for acquiring facilitative resources. Using the networking capability of smartphone to access digital content from the Internet to enrich conventional paper-based learning activities is worth investigating. This chapter introduces an augmentation-enhanced learning context with an integration of digital content into paper-based materials in order to facilitate learning. Constructive feedback, scaffolding questioning, and procedural scaffolding are three strategies applied into the instructional designs and learning system. Quasi-experiments for personal learning and collaborative learning were also conducted to evaluate the effects on learning performance. The results suggest that the three instructional designs had significantly positive effects on individual’s learning performance. Team’s learning performance and team’s discourse levels were promoted as well. This chapter lays out a strong foundation for researchers to further explore how to better design different learning strategies for different learning subjects in the augmentation-enhanced learning context using smartphones. It is hoped that educational practitioners are able to obtain concrete ideas and solutions on how to better leverage the benefits of both paper-based content and digital learning materials in a real blended learning environment.

This paper describes the current position of work on City University's Topsy project. Topsy is a new message passing multicomputer architecture. It comprises a fully Unix compatible distributed kernel, called Meshix, on top of a message based software system which in turn relies on new, high speed, communications hardware, Meshnet. A overview of the machine architecture and operating system is presented together with a discussion on the current implementation and further work.

Recent studies in science and engineering education support that inductive learning activities encouraging active student involvement may improve students’ motivation, development of soft skills and academic performance, compared to traditional lectures. Until recently, several technology-enhanced learning environments have been proposed to facilitate such activities in classrooms. However, these commonly depend on dedicated hardware devices, such as clickers or tablet PCs. Contrastingly, smartphones are being massively adopted by society as these become increasingly powerful and inexpensive. Even so, the use of smartphones as learning tools in lecture halls has still not been widely adopted. In this paper we present CollPhoto, a paper-plus-smartphone environment that supports face-to-face problem solving activities in the classroom. CollPhoto provides the instructor with instant visibility of students’ work, and facilitates him/her conducting discussions, based on a selection of students’ responses. We report on the design and initial validation of CollPhoto in the context of two computer science courses.

This study compares the performances of paper and electronic media during a reading task that includes frequent page turning. In the experiment, 18 subjects read multi-page documents aloud while referring to endnotes using paper, a large display, and a small display. Results revealed that reading from paper was 6.8% faster than reading from a large electronic display and 11.4% faster than reading from a small electronic display. No difference was found between scores of recognition tests of important words of documents among the three conditions, which indicates that paper is the most effective medium for people to read text speedily without reducing comprehension. Detailed analyses of the reading process show that, in the Paper condition, people perform both text reading and page-turning simultaneously. However, when using computer displays, reading and turning pages were divided completely and performed separately.

In this world of digital and social media booms, a number of people spend their valuable times burying heads in smartphones, resulting in unintentional increased gaps in physical relationship with people nearby. A hybrid digital-physical medium is a possible solution for this problem by means of externalizing social media data and integrating them into a physical medium somehow. In this way, using social media will simultaneously connect us with both virtual and physical worlds.

Nowadays, mobile devices are widely used as navigation aids, e.g., for car navigation. Their greatest advantage is the ability of automatic position tracking. In indoor environments, this feature is often not available, since indoor localization techniques are not ready for the mass-market yet. What remains is a small display with limited space for route visualizations. In contrast, the variable size of paper allows for the representation of additional context information as a means for spatial understanding and orientation in space, rendering it a valuable alternative presentation medium for indoor navigation aids. Independent of the medium used, provided visualizations must meet specific cartographic requirements like clarity, comprehensibility, and expedience. Within a co-operation between geoinformation science and sociology, we develop and investigate cartographic methods for effective route guidance in indoor environments. Our evaluation base comes from user studies conducted with more than 3,000 visitors, of both genders and aged between 4 and 78 years. These user studies were collected during the “Long Nights of Science” in Berlin in 2009, 2010, 2011, and 2012. We used paper as the presentation medium for our experiments, not only for practical reasons but also because we want to confront our participants with a solution which does not align to the current trend. Within this article we put special focus on media characteristics and users’ media preferences. Therefore, we asked our participants about their opinion on the provided paper maps in contrast to mobile solutions. Based on their answers, we could derive media characteristics relevant from a user’s perspective, as well as the affinities of different user groups. One astonishing outcome was that 11–15 year-old teenagers indicate a much higher tendency towards paper maps than towards smartphone apps.

With dramatic increasing of scientific research papers, scientific paper mining systems have become more popular for efficient paper retrieval and analysis. However, existing keyword based search engines, language or topic model based mining systems cannot provide customized queries according to various user requirements. Hence, in this paper, we are motivated to propose a novel TAIL (Time-Author-Institute-Literature) model to capture the relationships among literature, authors, institutes and time stamps. Based on the TAIL model, we implement the Massive Scientific Paper Mining (MSPM) system and set up a B/S (Browser/Server) structure for web services. The evaluation results on large real data show that our MSPM system could deliver desirable mining results, providing valuable data supports for scientific research cooperations.

This paper analyzes what stylistic characteristics differentiate different styles of writing, and specifically types of different A-level computer science articles. To do so, we compared various full papers using stylistic feature sets and a supervised machine learning method. We report on the success of this approach in identifying papers from the last 6 years of the following three conferences: SIGIR, ACL, and AAMAS. This approach achieves high accuracy results of 95.86%, 97.04%, 93.22%, and 92.14% for the following four classification experiments: (1) SIGIR / ACL, (2) SIGIR / AAMAS, (3) ACL / AAMAS, and (4) SIGIR / ACL / AAMAS, respectively. The Part of Speech (PoS) and the Orthographic sets were superior to all others and have been found as key components in different types of writing.

The goal of this research is to design a multi-label classification model which determines the research topics of a given technical paper. Based on the idea that papers are well organized and some parts of papers are more important than others for text classification, segments such as title, abstract, introduction and conclusion are intensively used in text representation. In addition, new features called Title Bi-Gram and Title SigNoun are used to improve the performance. The results of the experiments indicate that feature selection based on text segmentation and these two features are effective. Furthermore, we proposed a new model for text classification based on the structure of papers, called Back-off model, which achieves 60.45% Exact Match Ratio and 68.75% F-measure. It was also shown that Back-off model outperformed two existing methods, ML-kNN and Binary Approach.

This paper presents paper retrieval using the specific paper features chain and laid lines. Paper features are detected in digitized paper images and they are represented such that they could be used for retrieval. Optimal retrieval performance is achieved by means of a trainable similarity measure for a given set of paper features. By means of these methods a retrieval system is developed that art experts could use real-time in order to speed up their paper research.

RC4 is (still) a very widely-used stream cipher. Previous work by AlFardan et al. (USENIX Security 2013) and Paterson et al. (FSE 2014) exploited the presence of biases in the RC4 keystreams to mount plaintext recovery attacks against TLS-RC4 and WPA/TKIP. We improve on the latter work by performing large-scale computations to obtain accurate estimates of the single-byte and double-byte distributions in the early portions of RC4 keystreams for the WPA/TKIP context and by then using these distributions in a novel variant of the previous plaintext recovery attacks. The distribution computations were conducted using the Amazon EC2 cloud computing infrastructure and involved the coordination of 213 hyper-threaded cores running in parallel over a period of several days. We report on our experiences of computing at this scale using commercial cloud services. We also study Microsoft’s Point-to-Point Encryption protocol and its use of RC4, showing that it is also vulnerable to our attack techniques.

Memory transactions provide programmers with a convenient abstraction for concurrent programs: a keyword such as atomic designating a region of code that appears, from the perspective of concurrent threads, to execute atomically. Unfortunately, existing implementations in the form of software transactional memory STM are often ineffective due to their monolithic nature: every single read or write access is automatically tracked and recorded. In this statement, we advocate a transactional model of programming without a heavyweight software transactional memory, and describe some related, open research challenges. We suggest that a model based on persistent data structures could permit a variety of transactional algorithms to coexist in a library of composable transactional objects. Applications are constructed by snapping these objects together to form atomic transactions, in much the same way that today's Java programmers compose their applications from libraries such as java.util.concurrent. We report preliminary results developing this library in ScalaSTM, and discuss the challenges ahead.

U-Prove is a credential system that allows users to disclose information about themselves in a minimalistic way. Roughly speaking, in the U-Prove system a user obtains certified cryptographic tokens containing a set of attributes and is able to disclose a subset of his attributes to a verifier, while hiding the undisclosed attributes. In U-prove the actual identity of a token holder is hidden from verifiers, however each token has a static public key (i.e. token pseudonym), which makes a single token traceable, by what we mean that, if a token is presented twice to a verifier, then the verifier knows that it is the same token. We propose an extension to the U-Prove system which enables users to show U-Prove tokens in a blinded form, so even if a single token is presented twice, a verifier is not able to tell whether it is the same token or two distinct tokens. Our proposition is an optional extension, not changing the core of the U-Prove system. A verifier decides whether to use issuer signatures from U-Prove, or the blind certificates from the extension.

Since traditional statistics evaluation can’t completely be used to evaluate test paper composing because it is hardly to get score sample for no testing held, the multi-objective test paper evaluation is proposed to evaluate test paper composing with computer. The key method of proposed evaluation is to use the constraints defined in the outline of examination to establish the multi-objective of test and to use the absolute distance between temporary paper and final test paper to compute the degree of approximation. The experiments show that the proposed evaluation can evaluate test paper composing with computer, and the tradeoff can be got between the objective evaluation with computer and subjective evaluation with person.

With the increasing of the amount of the scientific papers, it is very important and difficult for paper-sharing platforms to recommend related papers accurately for users. This paper tackles the problem by proposing a method that models user historical behavior. Through collecting the operations on scientific papers of online users and carrying on the detailed analysis, we build preference model for each user. The personalized recommendation model is constructed based on content-based filtering model and statistical language model.. Experimental results show that users’ historical behavior plays an important role in user preference modeling and the proposed method improves the final predication performance in the field of technical papers recommendation.