Visible to the public Biblio

Filters: Keyword is ubiquitous computing  [Clear All Filters]
2019-01-31
Arfaoui, A., Kribeche, A., Boudia, O. R. M., Letaifa, A. Ben, Senouci, S. M., Hamdi, M..  2018.  Context-Aware Authorization and Anonymous Authentication in Wireless Body Area Networks. 2018 IEEE International Conference on Communications (ICC). :1–7.

With the pervasiveness of the Internet of Things (IoT) and the rapid progress of wireless communications, Wireless Body Area Networks (WBANs) have attracted significant interest from the research community in recent years. As a promising networking paradigm, it is adopted to improve the healthcare services and create a highly reliable ubiquitous healthcare system. However, the flourish of WBANs still faces many challenges related to security and privacy preserving. In such pervasive environment where the context conditions dynamically and frequently change, context-aware solutions are needed to satisfy the users' changing needs. Therefore, it is essential to design an adaptive access control scheme that can simultaneously authorize and authenticate users while considering the dynamic context changes. In this paper, we propose a context-aware access control and anonymous authentication approach based on a secure and efficient Hybrid Certificateless Signcryption (H-CLSC) scheme. The proposed scheme combines the merits of Ciphertext-Policy Attribute-Based Signcryption (CP-ABSC) and Identity-Based Broadcast Signcryption (IBBSC) in order to satisfy the security requirements and provide an adaptive contextual privacy. From a security perspective, it achieves confidentiality, integrity, anonymity, context-aware privacy, public verifiability, and ciphertext authenticity. Moreover, the key escrow and public key certificate problems are solved through this mechanism. Performance analysis demonstrates the efficiency and the effectiveness of the proposed scheme compared to benchmark schemes in terms of functional security, storage, communication and computational cost.

2019-01-21
Yu, Z., Du, H., Xiao, D., Wang, Z., Han, Q., Guo, B..  2018.  Recognition of Human Computer Operations Based on Keystroke Sensing by Smartphone Microphone. IEEE Internet of Things Journal. 5:1156–1168.
Human computer operations such as writing documents and playing games have become popular in our daily lives. These activities (especially if identified in a non-intrusive manner) can be used to facilitate context-aware services. In this paper, we propose to recognize human computer operations through keystroke sensing with a smartphone. Specifically, we first utilize the microphone embedded in a smartphone to sense the input audio from a computer keyboard. We then identify keystrokes using fingerprint identification techniques. The determined keystrokes are then corrected with a word recognition procedure, which utilizes the relations of adjacent letters in a word. Finally, by fusing both semantic and acoustic features, a classification model is constructed to recognize four typical human computer operations: 1) chatting; 2) coding; 3) writing documents; and 4) playing games. We recruited 15 volunteers to complete these operations, and evaluated the proposed approach from multiple aspects in realistic environments. Experimental results validated the effectiveness of our approach.
2018-12-10
Castiglione, A., Choo, K. Raymond, Nappi, M., Ricciardi, S..  2017.  Context Aware Ubiquitous Biometrics in Edge of Military Things. IEEE Cloud Computing. 4:16–20.

Edge computing can potentially play a crucial role in enabling user authentication and monitoring through context-aware biometrics in military/battlefield applications. For example, in Internet of Military Things (IoMT) or Internet of Battlefield Things (IoBT),an increasing number of ubiquitous sensing and computing devices worn by military personnel and embedded within military equipment (combat suit, instrumented helmets, weapon systems, etc.) are capable of acquiring a variety of static and dynamic biometrics (e.g., face, iris, periocular, fingerprints, heart-rate, gait, gestures, and facial expressions). Such devices may also be capable of collecting operational context data. These data collectively can be used to perform context-adaptive authentication in-the-wild and continuous monitoring of soldier's psychophysical condition in a dedicated edge computing architecture.

2018-09-12
Yousef, K. M. A., AlMajali, A., Hasan, R., Dweik, W., Mohd, B..  2017.  Security risk assessment of the PeopleBot mobile robot research platform. 2017 International Conference on Electrical and Computing Technologies and Applications (ICECTA). :1–5.
Nowadays, robots are widely ubiquitous and integral part in our daily lives, which can be seen almost everywhere in industry, hospitals, military, etc. To provide remote access and control, usually robots are connected to local network or to the Internet through WiFi or Ethernet. As such, it is of great importance and of a critical mission to maintain the safety and the security access of such robots. Security threats may result in completely preventing the access and control of the robot. The consequences of this may be catastrophic and may cause an immediate physical damage to the robot. This paper aims to present a security risk assessment of the well-known PeopleBot; a mobile robot platform from Adept MobileRobots Company. Initially, we thoroughly examined security threats related to remote accessing the PeopleBot robot. We conducted an impact-oriented analysis approach on the wireless communication medium; the main method considered to remotely access the PeopleBot robot. Numerous experiments using SSH and server-client applications were conducted, and they demonstrated that certain attacks result in denying remote access service to the PeopleBot robot. Consequently and dangerously the robot becomes unavailable. Finally, we suggested one possible mitigation and provided useful conclusions to raise awareness of possible security threats on the robotic systems; especially when the robots are involved in critical missions or applications.
2018-06-20
Chowdhury, S. K., Sen, M..  2017.  Attacks and mitigation techniques on mobile ad hoc network \#x2014; A survey. 2017 International Conference on Trends in Electronics and Informatics (ICEI). :11–18.

A mobile ad hoc network is a type of ad hoc network in which node changes it locations and configures them. It uses wireless medium to communicate with other networks. It also does not possess centralized authority and each node has the ability to perform some tasks. Nodes in this type of network has a routing table depending on which it finds the optimal way to send packets in forward direction but link failure should be updated in node table to encompass that. In civilian environment like meeting rooms, cab networking etc, in military search and rescue operations it has huge application.

2018-06-11
Manishankar, S., Arjun, C. S., Kumar, P. R. A..  2017.  An authorized security middleware for managing on demand infrastructure in cloud. 2017 International Conference on Intelligent Computing and Control (I2C2). :1–5.
Recent increases in the field of infrastructure has led to the emerging of cloud computing a virtualized computing platform. This technology provides a lot of pros like rapid elasticity, ubiquitous network access and on-demand access etc. Compare to other technologies cloud computing provides many essential services. As the elasticity and scalability increases the chance for vulnerability of the system is also high. There are many known and unknown security risks and challenges present in this environment. In this research an environment is proposed which can handle security issues and deploys various security levels. The system handles the security of various infrastructure like VM and also handles the Dynamic infrastructure request control. One of the key feature of proposed approach is Dual authorization in which all account related data will be authorized by two privileged administrators of the cloud. The auto scalability feature of the cloud is be made secure for on-demand service request handling by providing an on-demand scheduler who will process the on-demand request and assign the required infrastructure. Combining these two approaches provides a secure environment for cloud users as well as handle On-demand Infrastructure request.
Ding, W., Wang, J., Lu, K., Zhao, R., Wang, X., Zhu, Y..  2017.  Optimal Cache Management and Routing for Secure Content Delivery in Information-Centric Networks with Network Coding. 2017 IEEE International Symposium on Parallel and Distributed Processing with Applications and 2017 IEEE International Conference on Ubiquitous Computing and Communications (ISPA/IUCC). :267–274.

Information-Centric Network (ICN) is one of the most promising network architecture to handle the problem of rapid increase of data traffic because it allows in-network cache. ICNs with Linear Network Coding (LNC) can greatly improve the performance of content caching and delivery. In this paper, we propose a Secure Content Caching and Routing (SCCR) framework based on Software Defined Network (SDN) to find the optimal cache management and routing for secure content delivery, which aims to firstly minimize the total cost of cache and bandwidth consumption and then minimize the usage of random chunks to guarantee information theoretical security (ITS). Specifically, we firstly propose the SCCR problem and then introduce the main ideas of the SCCR framework. Next, we formulate the SCCR problem to two Linear Programming (LP) formulations and design the SCCR algorithm based on them to optimally solve the SCCR problem. Finally, extensive simulations are conducted to evaluate the proposed SCCR framework and algorithms.

2018-03-26
Alexopoulos, N., Daubert, J., Mühlhäuser, M., Habib, S. M..  2017.  Beyond the Hype: On Using Blockchains in Trust Management for Authentication. 2017 IEEE Trustcom/BigDataSE/ICESS. :546–553.

Trust Management (TM) systems for authentication are vital to the security of online interactions, which are ubiquitous in our everyday lives. Various systems, like the Web PKI (X.509) and PGP's Web of Trust are used to manage trust in this setting. In recent years, blockchain technology has been introduced as a panacea to our security problems, including that of authentication, without sufficient reasoning, as to its merits.In this work, we investigate the merits of using open distributed ledgers (ODLs), such as the one implemented by blockchain technology, for securing TM systems for authentication. We formally model such systems, and explore how blockchain can help mitigate attacks against them. After formal argumentation, we conclude that in the context of Trust Management for authentication, blockchain technology, and ODLs in general, can offer considerable advantages compared to previous approaches. Our analysis is, to the best of our knowledge, the first to formally model and argue about the security of TM systems for authentication, based on blockchain technology. To achieve this result, we first provide an abstract model for TM systems for authentication. Then, we show how this model can be conceptually encoded in a blockchain, by expressing it as a series of state transitions. As a next step, we examine five prevalent attacks on TM systems, and provide evidence that blockchain-based solutions can be beneficial to the security of such systems, by mitigating, or completely negating such attacks.

2018-03-05
Ehrlich, M., Wisniewski, L., Trsek, H., Mahrenholz, D., Jasperneite, J..  2017.  Automatic Mapping of Cyber Security Requirements to Support Network Slicing in Software-Defined Networks. 2017 22nd IEEE International Conference on Emerging Technologies and Factory Automation (ETFA). :1–4.
The process of digitalisation has an advanced impact on social lives, state affairs, and the industrial automation domain. Ubiquitous networks and the increased requirements in terms of Quality of Service (QoS) create the demand for future-proof network management. Therefore, new technological approaches, such as Software-Defined Networks (SDN) or the 5G Network Slicing concept, are considered. However, the important topic of cyber security has mainly been ignored in the past. Recently, this topic has gained a lot of attention due to frequently reported security related incidents, such as industrial espionage, or production system manipulations. Hence, this work proposes a concept for adding cyber security requirements to future network management paradigms. For this purpose, various security related standards and guidelines are available. However, these approaches are mainly static, require a high amount of manual efforts by experts, and need to be performed in a steady manner. Therefore, the proposed solution contains a dynamic, machine-readable, automatic, continuous, and future-proof approach to model and describe cyber security QoS requirements for the next generation network management.
Ehrlich, M., Wisniewski, L., Trsek, H., Mahrenholz, D., Jasperneite, J..  2017.  Automatic Mapping of Cyber Security Requirements to Support Network Slicing in Software-Defined Networks. 2017 22nd IEEE International Conference on Emerging Technologies and Factory Automation (ETFA). :1–4.
The process of digitalisation has an advanced impact on social lives, state affairs, and the industrial automation domain. Ubiquitous networks and the increased requirements in terms of Quality of Service (QoS) create the demand for future-proof network management. Therefore, new technological approaches, such as Software-Defined Networks (SDN) or the 5G Network Slicing concept, are considered. However, the important topic of cyber security has mainly been ignored in the past. Recently, this topic has gained a lot of attention due to frequently reported security related incidents, such as industrial espionage, or production system manipulations. Hence, this work proposes a concept for adding cyber security requirements to future network management paradigms. For this purpose, various security related standards and guidelines are available. However, these approaches are mainly static, require a high amount of manual efforts by experts, and need to be performed in a steady manner. Therefore, the proposed solution contains a dynamic, machine-readable, automatic, continuous, and future-proof approach to model and describe cyber security QoS requirements for the next generation network management.
2018-02-06
Mispan, M. S., Halak, B., Zwolinski, M..  2017.  Lightweight Obfuscation Techniques for Modeling Attacks Resistant PUFs. 2017 IEEE 2nd International Verification and Security Workshop (IVSW). :19–24.

Building lightweight security for low-cost pervasive devices is a major challenge considering the design requirements of a small footprint and low power consumption. Physical Unclonable Functions (PUFs) have emerged as a promising technology to provide a low-cost authentication for such devices. By exploiting intrinsic manufacturing process variations, PUFs are able to generate unique and apparently random chip identifiers. Strong-PUFs represent a variant of PUFs that have been suggested for lightweight authentication applications. Unfortunately, many of the Strong-PUFs have been shown to be susceptible to modelling attacks (i.e., using machine learning techniques) in which an adversary has access to challenge and response pairs. In this study, we propose an obfuscation technique during post-processing of Strong-PUF responses to increase the resilience against machine learning attacks. We conduct machine learning experiments using Support Vector Machines and Artificial Neural Networks on two Strong-PUFs: a 32-bit Arbiter-PUF and a 2-XOR 32-bit Arbiter-PUF. The predictability of the 32-bit Arbiter-PUF is reduced to $\approx$ 70% by using an obfuscation technique. Combining the obfuscation technique with 2-XOR 32-bit Arbiter-PUF helps to reduce the predictability to $\approx$ 64%. More reduction in predictability has been observed in an XOR Arbiter-PUF because this PUF architecture has a good uniformity. The area overhead with an obfuscation technique consumes only 788 and 1080 gate equivalents for the 32-bit Arbiter-PUF and 2-XOR 32-bit Arbiter-PUF, respectively.

Sain, M., Bruce, N., Kim, K. H., Lee, H. J..  2017.  A Communication Security Protocol for Ubiquitous Sensor Networks. 2017 19th International Conference on Advanced Communication Technology (ICACT). :228–231.

The data accessibility anytime and anywhere is nowadays the key feature for information technology enabled by the ubiquitous network system for huge applications. However, security and privacy are perceived as primary obstacles to its wide adoption when it is applied to the end user application. When sharing sensitive information, personal s' data protection is the paramount requirement for the security and privacy to ensure the trustworthiness of the service provider. To this end, this paper proposes communication security protocol to achieve data protection when a user is sending his sensitive data to the network through gateway. We design a cipher content and key exchange computation process. Finally, the performance analysis of the proposed scheme ensure the honesty of the gateway service provider, since the user has the ability to control who has access to his data by issuing a cryptographic access credential to data users.

Brunner, M., Sillaber, C., Breu, R..  2017.  Towards Automation in Information Security Management Systems. 2017 IEEE International Conference on Software Quality, Reliability and Security (QRS). :160–167.

Establishing and operating an Information Security Management System (ISMS) to protect information values and information systems is in itself a challenge for larger enterprises and small and medium sized businesses alike. A high level of automation is required to reduce operational efforts to an acceptable level when implementing an ISMS. In this paper we present the ADAMANT framework to increase automation in information security management as a whole by establishing a continuous risk-driven and context-aware ISMS that not only automates security controls but considers all highly interconnected information security management tasks. We further illustrate how ADAMANT is suited to establish an ISO 27001 compliant ISMS for small and medium-sized enterprises and how not only the monitoring of security controls but a majority of ISMS related activities can be supported through automated process execution and workflow enactment.

Bhattacharya, S., Kumar, C. R. S..  2017.  Ransomware: The CryptoVirus Subverting Cloud Security. 2017 International Conference on Algorithms, Methodology, Models and Applications in Emerging Technologies (ICAMMAET). :1–6.

Cloud computing presents unlimited prospects for Information Technology (IT) industry and business enterprises alike. Rapid advancement brings a dark underbelly of new vulnerabilities and challenges unfolding with alarming regularity. Although cloud technology provides a ubiquitous environment facilitating business enterprises to conduct business across disparate locations, security effectiveness of this platform interspersed with threats which can bring everything that subscribes to the cloud, to a halt raises questions. However advantages of cloud platforms far outweighs drawbacks and study of new challenges helps overcome drawbacks of this technology. One such emerging security threat is of ransomware attack on the cloud which threatens to hold systems and data on cloud network to ransom with widespread damaging implications. This provides huge scope for IT security specialists to sharpen their skillset to overcome this new challenge. This paper covers the broad cloud architecture, current inherent cloud threat mechanisms, ransomware vulnerabilities posed and suggested methods to mitigate it.

Moustafa, N., Creech, G., Sitnikova, E., Keshk, M..  2017.  Collaborative Anomaly Detection Framework for Handling Big Data of Cloud Computing. 2017 Military Communications and Information Systems Conference (MilCIS). :1–6.

With the ubiquitous computing of providing services and applications at anywhere and anytime, cloud computing is the best option as it offers flexible and pay-per-use based services to its customers. Nevertheless, security and privacy are the main challenges to its success due to its dynamic and distributed architecture, resulting in generating big data that should be carefully analysed for detecting network's vulnerabilities. In this paper, we propose a Collaborative Anomaly Detection Framework (CADF) for detecting cyber attacks from cloud computing environments. We provide the technical functions and deployment of the framework to illustrate its methodology of implementation and installation. The framework is evaluated on the UNSW-NB15 dataset to check its credibility while deploying it in cloud computing environments. The experimental results showed that this framework can easily handle large-scale systems as its implementation requires only estimating statistical measures from network observations. Moreover, the evaluation performance of the framework outperforms three state-of-the-art techniques in terms of false positive rate and detection rate.

2017-12-12
Bhattacharjee, S. Das, Yuan, J., Jiaqi, Z., Tan, Y. P..  2017.  Context-aware graph-based analysis for detecting anomalous activities. 2017 IEEE International Conference on Multimedia and Expo (ICME). :1021–1026.

This paper proposes a context-aware, graph-based approach for identifying anomalous user activities via user profile analysis, which obtains a group of users maximally similar among themselves as well as to the query during test time. The main challenges for the anomaly detection task are: (1) rare occurrences of anomalies making it difficult for exhaustive identification with reasonable false-alarm rate, and (2) continuously evolving new context-dependent anomaly types making it difficult to synthesize the activities apriori. Our proposed query-adaptive graph-based optimization approach, solvable using maximum flow algorithm, is designed to fully utilize both mutual similarities among the user models and their respective similarities with the query to shortlist the user profiles for a more reliable aggregated detection. Each user activity is represented using inputs from several multi-modal resources, which helps to localize anomalies from time-dependent data efficiently. Experiments on public datasets of insider threats and gesture recognition show impressive results.

2017-11-20
Chaisiri, S., Ko, R. K. L..  2016.  From Reactionary to Proactive Security: Context-Aware Security Policy Management and Optimization under Uncertainty. 2016 IEEE Trustcom/BigDataSE/ISPA. :535–543.

At the core of its nature, security is a highly contextual and dynamic challenge. However, current security policy approaches are usually static, and slow to adapt to ever-changing requirements, let alone catching up with reality. In a 2012 Sophos survey, it was stated that a unique malware is created every half a second. This gives a glimpse of the unsustainable nature of a global problem, any improvement in terms of closing the "time window to adapt" would be a significant step forward. To exacerbate the situation, a simple change in threat and attack vector or even an implementation of the so-called "bring-your-own-device" paradigm will greatly change the frequency of changed security requirements and necessary solutions required for each new context. Current security policies also typically overlook the direct and indirect costs of implementation of policies. As a result, technical teams often fail to have the ability to justify the budget to the management, from a business risk viewpoint. This paper considers both the adaptive and cost-benefit aspects of security, and introduces a novel context-aware technique for designing and implementing adaptive, optimized security policies. Our approach leverages the capabilities of stochastic programming models to optimize security policy planning, and our preliminary results demonstrate a promising step towards proactive, context-aware security policies.

2017-09-05
Luo, Chu, Fylakis, Angelos, Partala, Juha, Klakegg, Simon, Goncalves, Jorge, Liang, Kaitai, Seppänen, Tapio, Kostakos, Vassilis.  2016.  A Data Hiding Approach for Sensitive Smartphone Data. Proceedings of the 2016 ACM International Joint Conference on Pervasive and Ubiquitous Computing. :557–568.

We develop and evaluate a data hiding method that enables smartphones to encrypt and embed sensitive information into carrier streams of sensor data. Our evaluation considers multiple handsets and a variety of data types, and we demonstrate that our method has a computational cost that allows real-time data hiding on smartphones with negligible distortion of the carrier stream. These characteristics make it suitable for smartphone applications involving privacy-sensitive data such as medical monitoring systems and digital forensics tools.

2017-08-22
Luo, Chu, Fylakis, Angelos, Partala, Juha, Klakegg, Simon, Goncalves, Jorge, Liang, Kaitai, Seppänen, Tapio, Kostakos, Vassilis.  2016.  A Data Hiding Approach for Sensitive Smartphone Data. Proceedings of the 2016 ACM International Joint Conference on Pervasive and Ubiquitous Computing. :557–568.

We develop and evaluate a data hiding method that enables smartphones to encrypt and embed sensitive information into carrier streams of sensor data. Our evaluation considers multiple handsets and a variety of data types, and we demonstrate that our method has a computational cost that allows real-time data hiding on smartphones with negligible distortion of the carrier stream. These characteristics make it suitable for smartphone applications involving privacy-sensitive data such as medical monitoring systems and digital forensics tools.

2017-02-23
G. DAngelo, S. Rampone, F. Palmieri.  2015.  "An Artificial Intelligence-Based Trust Model for Pervasive Computing". 2015 10th International Conference on P2P, Parallel, Grid, Cloud and Internet Computing (3PGCIC). :701-706.

Pervasive Computing is one of the latest and more advanced paradigms currently available in the computers arena. Its ability to provide the distribution of computational services within environments where people live, work or socialize leads to make issues such as privacy, trust and identity more challenging compared to traditional computing environments. In this work we review these general issues and propose a Pervasive Computing architecture based on a simple but effective trust model that is better able to cope with them. The proposed architecture combines some Artificial Intelligence techniques to achieve close resemblance with human-like decision making. Accordingly, Apriori algorithm is first used in order to extract the behavioral patterns adopted from the users during their network interactions. Naïve Bayes classifier is then used for final decision making expressed in term of probability of user trustworthiness. To validate our approach we applied it to some typical ubiquitous computing scenarios. The obtained results demonstrated the usefulness of such approach and the competitiveness against other existing ones.

2015-05-06
Al-Anzi, F.S., Salman, A.A., Jacob, N.K., Soni, J..  2014.  Towards robust, scalable and secure network storage in Cloud Computing. Digital Information and Communication Technology and it's Applications (DICTAP), 2014 Fourth International Conference on. :51-55.

The term Cloud Computing is not something that appeared overnight, it may come from the time when computer system remotely accessed the applications and services. Cloud computing is Ubiquitous technology and receiving a huge attention in the scientific and industrial community. Cloud computing is ubiquitous, next generation's in-formation technology architecture which offers on-demand access to the network. It is dynamic, virtualized, scalable and pay per use model over internet. In a cloud computing environment, a cloud service provider offers “house of resources” includes applications, data, runtime, middleware, operating system, virtualization, servers, data storage and sharing and networking and tries to take up most of the overhead of client. Cloud computing offers lots of benefits, but the journey of the cloud is not very easy. It has several pitfalls along the road because most of the services are outsourced to third parties with added enough level of risk. Cloud computing is suffering from several issues and one of the most significant is Security, privacy, service availability, confidentiality, integrity, authentication, and compliance. Security is a shared responsibility of both client and service provider and we believe security must be information centric, adaptive, proactive and built in. Cloud computing and its security are emerging study area nowadays. In this paper, we are discussing about data security in cloud at the service provider end and proposing a network storage architecture of data which make sure availability, reliability, scalability and security.

2015-05-05
Boleng, J., Novakouski, M., Cahill, G., Simanta, S., Morris, E..  2014.  Fusing Open Source Intelligence and Handheld Situational Awareness: Benghazi Case Study. Military Communications Conference (MILCOM), 2014 IEEE. :1421-1426.

This paper reports the results and findings of a historical analysis of open source intelligence (OSINT) information (namely Twitter data) surrounding the events of the September 11, 2012 attack on the US Diplomatic mission in Benghazi, Libya. In addition to this historical analysis, two prototype capabilities were combined for a table top exercise to explore the effectiveness of using OSINT combined with a context aware handheld situational awareness framework and application to better inform potential responders as the events unfolded. Our experience shows that the ability to model sentiment, trends, and monitor keywords in streaming social media, coupled with the ability to share that information to edge operators can increase their ability to effectively respond to contingency operations as they unfold.
 

Arimura, S., Fujita, M., Kobayashi, S., Kani, J., Nishigaki, M., Shiba, A..  2014.  i/k-Contact: A context-aware user authentication using physical social trust. Privacy, Security and Trust (PST), 2014 Twelfth Annual International Conference on. :407-413.

In recent years, with growing demands towards big data application, various research on context-awareness has once again become active. This paper proposes a new type of context-aware user authentication that controls the authentication level of users, using the context of “physical trust relationship” that is built between users by visual contact. In our proposal, the authentication control is carried out by two mechanisms; “i-Contact” and “k-Contact”. i-Contact is the mechanism that visually confirms the user (owner of a mobile device) using the surrounding users' eyes. The authenticity of users can be reliably assessed by the people (witnesses), even when the user exhibits ambiguous behavior. k-Contact is the mechanism that dynamically changes the authentication level of each user using the context information collected through i-Contact. Once a user is authenticated by eyewitness reports, the user is no longer prompted for a password to unlock his/her mobile device and/or to access confidential resources. Thus, by leveraging the proposed authentication system, the usability for only trusted users can be securely enhanced. At the same time, our proposal anticipates the promotion of physical social communication as face-to-face communication between users is triggered by the proposed authentication system.
 

2015-05-04
Durmus, Y., Langendoen, K..  2014.  Wifi authentication through social networks #x2014; A decentralized and context-aware approach. Pervasive Computing and Communications Workshops (PERCOM Workshops), 2014 IEEE International Conference on. :532-538.

With the proliferation of WiFi-enabled devices, people expect to be able to use them everywhere, be it at work, while commuting, or when visiting friends. In the latter case, home owners are confronted with the burden of controlling the access to their WiFi router, and usually resort to simply sharing the password. Although convenient, this solution breaches basic security principles, and puts the burden on the friends who have to enter the password in each and every of their devices. The use of social networks, specifying the trust relations between people and devices, provides for a more secure and more friendly authentication mechanism. In this paper, we progress the state-of-the-art by abandoning the centralized solution to embed social networks in WiFi authentication; we introduce EAP-SocTLS, a decentralized approach for authentication and authorization of WiFi access points and other devices, exploiting the embedded trust relations. In particular, we address the (quadratic) search complexity when indirect trust relations, like the smartphone of a friend's kid, are involved. We show that the simple heuristic of limiting the search to friends and devices in physical proximity makes for a scalable solution. Our prototype implementation, which is based on WebID and EAP-TLS, uses WiFi probe requests to determine the pool of neighboring devices and was shown to reduce the search time from 1 minute for the naive policy down to 11 seconds in the case of granting access over an indirect friend.
 

Ziegler, D., Rauter, M., Stromberger, C., Teufl, P., Hein, D..  2014.  Do you think your passwords are secure? Privacy and Security in Mobile Systems (PRISMS), 2014 International Conference on. :1-8.

Many systems rely on passwords for authentication. Due to numerous accounts for different services, users have to choose and remember a significant number of passwords. Password-Manager applications address this issue by storing the user's passwords. They are especially useful on mobile devices, because of the ubiquitous access to the account passwords. Password-Managers often use key derivation functions to convert a master password into a cryptographic key suitable for encrypting the list of passwords, thus protecting the passwords against unauthorized, off-line access. Therefore, design and implementation flaws in the key derivation function impact password security significantly. Design and implementation problems in the key derivation function can render the encryption on the password list useless, by for example allowing efficient bruteforce attacks, or - even worse - direct decryption of the stored passwords. In this paper, we analyze the key derivation functions of popular Android Password-Managers with often startling results. With this analysis, we want to raise the awareness of developers of security critical apps for security, and provide an overview about the current state of implementation security of security-critical applications.