A novel word-independent gesture-typing continuous authentication scheme for mobile devices

In this study, we produce a new continuous authentication scheme for gesture-typing on mobile devices. Our scheme is the first scheme that authenticates gesture-typing interactions in a word-independent format. The scheme relies on groupings of features extracted from the word gesture after it has been reduced to parts common to all gestures. We show that movement sensors are also important in differentiating between users. We describe the feature extraction processes and analyse our proposed feature set. The unique process of our authentication scheme is presented and described. We collect our own gesture typing dataset including data collected during sitting, standing and walking activities for realism. We test our features against state-of-the-art touch-screen interaction features and compare feature extraction times on real mobile devices. Our scheme authenticates users with an equal error rate of 3.58% for a single word-gesture. The equal error rate is reduced to 0.81% when 3 word-gestures are used to authenticate

Evaluating the Provision of Botnet Defences using Translational Research Concepts.

Botnet research frequently draws on concepts from other fields. An example is the use of epidemiological models when studying botnet propagation, which facilitate an understanding of bot spread dynamics and the exploration of behavioural theory. Whilst the literature is rich with these models, it is lacking in work aimed at connecting the insights of theoretical research with day-to-day practice. To address this, we look at botnets through the lens of implementation science, a discipline from the field of translational research in health care, which is designed to evaluate the implementation process. In this paper, we explore key concepts of implementation science, and propose a framework-based approach to improve the provision of security measures to network entities. We demonstrate the approach using existing propagation models, and discuss the role of implementation science in malware defence

Modelling the Spread of Botnet Malware in IoT-Based Wireless Sensor Networks

The propagation approach of a botnet largely dictates its formation, establishing a foundation of bots for future exploitation. The chosen propagation method determines the attack surface, and consequently, the degree of network penetration, as well as the overall size and the eventual attack potency. It is therefore essential to understand propagation behaviours and influential factors in order to better secure vulnerable systems. Whilst botnet propagation is generally well-studied, newer technologies like IoT have unique characteristics which are yet to be thoroughly explored. In this paper, we apply the principles of epidemic modelling to IoT networks consisting of wireless sensor nodes. We build IoT-SIS, a novel propagation model which considers the impact of IoT-specific characteristics like limited processing power, energy restrictions, and node density on the formation of a botnet. Focusing on worm-based propagation, this model is used to explore the dynamics of spread using numerical simulations and the Monte Carlo method, and to discuss the real-life implications of our findings

Secure Anonymous Routing for MANETs Using Distributed Dynamic Random Path Selection

Most of the MANET security research has so far focused on providing routing security and confidentiality to the data packets, but less has been done to ensure privacy and anonymity of the communicating entities. In this paper, we propose a routing protocol which ensures anonymity, privacy of the user. This is achieved by randomly selecting next hop at each intermediate. This protocol also provides data security using public key ciphers. The protocol is simulated using in-house simulator written in C with OpenSSL crypto APIs. The robustness of our protocol is evaluated against known security attacks

Patient privacy protection using anonymous access control techniques

Objective: The objective of this study is to develop a solution to preserve security and privacy in a healthcare environment where health-sensitive information will be accessed by many parties and stored in various distributed databases. The solution should maintain anonymous medical records and it should be able to link anonymous medical information in distributed databases into a single patient medical record with the patient identity. Methods: In this paper we present a protocol that can be used to authenticate and authorize patients to healthcare services without providing the patient identification. Healthcare service can identify the patient using separate temporary identities in each identification session and medical records are linked to these temporary identities. Temporary identities can be used to enable record linkage and reverse track real patient identity in critical medical situations. Results: The proposed protocol provides main security and privacy services such as user anonymity, message privacy, message confidentiality, user authentication, user authorization and message replay attacks. The medical environment validates the patient at the healthcare service as a real and registered patient for the medical services. Using the proposed protocol, the patient anonymous medical records at different healthcare services can be linked into one single report and it is possible to securely reverse track anonymous patient into the real identity. Conclusion: The protocol protects the patient privacy with a secure anonymous authentication to healthcare services and medical record registries according to the European and the UK legislations, where the patient real identity is not disclosed with the distributed patient medical records

HP-sequence design for lattice proteins - an exact enumeration study on diamond as well as square lattice

We present an exact enumeration algorithm for identifying the {\it native} configuration - a maximally compact self avoiding walk configuration that is also the minimum energy configuration for a given set of contact-energy schemes; the process is implicitly sequence-dependent. In particular, we show that the 25-step native configuration on a diamond lattice consists of two sheet-like structures and is the same for all the contact-energy schemes, ${(-1,0,0);(-7,-3,0); (-7,-3,-1); (-7,-3,1)}$; on a square lattice also, the 24-step native configuration is independent of the energy schemes considered. However, the designing sequence for the diamond lattice walk depends on the energy schemes used whereas that for the square lattice walk does not. We have calculated the temperature-dependent specific heat for these designed sequences and the four energy schemes using the exact density of states. These data show that the energy scheme $(-7,-3,-1)$ is preferable to the other three for both diamond and square lattice because the associated sequences give rise to a sharp low-temperature peak. We have also presented data for shorter (23-, 21- and 17-step) walks on a diamond lattice to show that this algorithm helps identify a unique minimum energy configuration by suitably taking care of the ground-state degeneracy. Interestingly, all these shorter target configurations also show sheet-like secondary structures.Comment: 19 pages, 7 figures (eps), 11 tables (latex files

Novel framework for secure mobile financial services

The financial sector is always looking for new services delivery platforms to improve customer confidence and satisfaction. To achieve this, the banking service delivery platform must provide end-to-end security to safeguard the financial information exchanged between the bank and the customer. Today a number of banks offer mobile banking service to their customers. However, still banks have been adopting the generic user authentication systems that were developed for the desktop environment based on two-factor authentication with a number of user intrusive activities. This paper presents a novel authentication and authorization framework for secure mobile banking applications based on the user SIM and mobile credentials

A study on the diversity and production of microbial extracellular nucleases :potential anti-biofilm enzymes

PhD ThesisMicroorganisms have been viewed as planktonic, free living single cells but predominantly they exist as sessile multispecies communities in the natural environment forming ‘biofilms’. Biofilms are beneficial for organisms to survive in natural environment as well as for biotechnological applications such as microbial fuel cells and bioremediation. However, biofilms are associated with disease persistence and biofouling and are comprised of adhered microbes within a hydrated matrix rich in polysaccharides, proteins and extracellular DNA (eDNA). eDNA is an important structural component and its degradation by deoxyribonucleases may be a novel approach to eradicate biofilm related problems. The present work was undertaken in this context to discover and produce microbial nucleolytic enzymes for applications for the control of harmful biofilms. Eighty six out of 260 bacterial isolates which included thermophilic and psychrophilic strains, showed deoxyribonuclease activity. The diversity and function of extracellular nucleases was also investigated throughout the microbial world using bioinformatics tools. Sequence driven analysis suggested that major bacterial lineages contain diverse extracellular nucleases with biological function related to nitrogen, phosphate and carbohydrate metabolism, protection, survival and virulence. Production optimisation for one specific extracellular nuclease, NucB, from Bacillus licheniformis EI-34-6 was carried out. This enzyme was previously known to cleave eDNA causing biofilm dispersal, and may therefore be used commercially to remove biofilms. The understanding of B. licheniformis physiology was applied in order to enhance NucB production 10-fold. For further characterisation of the enzyme and to Abstract iv understand its biological mechanism in breaking down biofilms, NucB was expressed in the SURE expression host B. subtilis NZ8900. This allowed a 68-fold increase in protein yield. NucB protein has been purified to high degree purity with specific nuclease activity of 15000 U/mg of protein. Biophysical characterisation showed that the protein was thermally stable and could reversibly refold. Statistical optimisation of extracellular nucleases production in diverse bacteria grown at different temperatures was demonstrated as a promising methodology for enhancing key enzyme secretion. The effectiveness of biofilm disruption by NucB was successfully tested with different single species biofilms grown on polystyrene, glass, and stainless steel surfaces. Biofilm dispersal efficiency of other microbial nucleases ranged between 60 – 95 % of removal after 1 h. The results presented in this thesis demonstrate that bacteria were able to produce nucleases across broad temperature range. In context to biofilm dispersal, bioinformatic analysis speculates the ecological implication of secreted diverse microbial extracellular nuclease-like genes were to decide the fate of eDNA and play pivotal role in nutrient cycling of the eco-system. Bioprocess development confirmed process optimisation can reliably produce functional and well-folded recombinant NucB at levels suitable for applications where biofilm removal is needed. Production optimisation of extracellular nucleases from diverse bacteria expanded the availability of different nucleases with wide range of anti-biofilm properties. Evidence is also presented to show that extracellular nucleases can disperse preformed microbial biofilms on different substrata. Microbial extracellular nucleases therefore appear to be a rich and unexplored source of anti-biofilm enzymes

Hydrodynamic aspects of airlift contactors

This study deals with gas void fraction, liquid circulation velocity and liquid mixing in airlift contactors. Experimental measurements of gas holdup, liquid velocity, mixing and circulation times, Bodenstein number and liquid phase axial dispersion coefficient were obtained with various Newtonian and non-Newtonian fluids using different reactor configurations. The experimental data were obtained in two distinct laboratory scale draft tube internal loop airlift devices (52 L) and an external loop airlift contactor (35 L).The effect of superficial gas velocity (low to intermediate range), liquid properties (salt concentration and liquid viscosity), two immiscible liquid phases (oil/water) and reactor geometry on the gas holdup, liquid velocity and liquid mixing in airlift vessels were examined. Gas holdup was observed to increase with increasing gas velocity, liquid phase electrolyte concentration and Newtonian and pseudoplastic non-Newtonian liquid viscosity. The effect of the two immiscible liquid phases on gas holdup was relatively complex. Initially, on addition of oil to the continuous phase (water) there was a sharp increase in gas holdup. As the concentration of oil-in-water emulsion increased the gas holdup was observed to decrease and then increase as the pure oil limit was reached. The liquid velocity and liquid phase mixing in the airlift vessel improved with increasing gas flow rate. But, with an increase in electrolyte concentration, liquid viscosity and oil-in-water emulsion concentration the superficial liquid velocity decreased. Hence, the liquid mixing was found to deteriorate with increasing salt concentration, liquid viscosity and oil-in-water emulsion concentration. For a fixed gas velocity, the local Bodenstein numbers and axial dispersion coefficients indicated that the mixing in the airlift contactor was not uniform in the different regions of the vessel. The downcomer section gave considerably higher axial dispersion coefficient values compared to the riser section for a given gas flow rate. The riser and downcomer Bo numbers indicated that the liquid flow in the riser section approached plug flow, while the flow in the downcomer section was reasonably well mixed. The liquid mixing in the reactor as a whole was somewhere in- between the mixing in the riser and downcomer sections. A hydrodynamic model was employed to estimate the riser gas holdup and liquid velocity in the airlift vessels. This model was developed using a drift flux model together with an energy balance over an airlift loop. Model predictions were compared with experimental data obtained in this study. In addition, suitable experimental data available in previous literature were used. The applicability of the model to a broad range of airlift reactor types (split-cylinder and draft tube internal loops; external loop) and scales (0.033 m3 ≤ V ≤ 1.058 m3; 1.220 m ≤ Ht ≤ 5.076 m; 0.11 ≤ Ad/Ar ≤ 1.45) and with various Newtonian and non-Newtonian liquids is demonstrated. For non-Newtonian media in airlift vessels, a correlation for average shear rate was also developed. This relationship considers the effect of gas holdup, liquid velocity and flow behaviour index on shear rate. A higher apparent liquid viscosity gave a lower average shear rate in the vessel than a lower apparent viscosity, at a given superficial gas velocity

Security analysis of the micro transport protocol with a misbehaving receiver

BitTorrent is the most widely used Peer-to-Peer (P2P) protocol and it comprises the largest share of traffic in Europe. To make BitTorrent more Internet Service Provider (ISP) friendly, BitTorrent Inc. invented the Micro Transport Protocol (uTP). It is based on UDP with a novel congestion control called Low Extra Delay Background Transport (LEDBAT). This protocol assumes that the receiver always gives correct feedback, since otherwise this deteriorates throughput or yields to corrupted data. We show through experimental investigation that a misbehaving uTP receiver, which is not interested in data integrity, can increase the bandwidth of the sender by up to five times. This can cause a congestion collapse and steal large share of a victim’s bandwidth. We present three attacks, which increase the bandwidth usage significantly. We have tested these attacks in a real world environment and show its severity both in terms of number of packets and total traffic generated. We also present a countermeasure for protecting against the attacks and evaluate the performance of that defence strategy