title: Good vibrations: artificial ambience-based relay attack detection

authors: Gurulian, Iakovos

subjects: computer science

abstract: Relay attacks are passive man in the middle attacks, aiming to extend the physical distance of devices involved in a transaction beyond their operating environment, within the restricted time-frame. In the field of smartphones, proposals have been put forward suggesting sensing the natural ambient environment as an effective Proximity and Relay Attack Detection (PRAD) mechanism. However, these proposals are not in compliance with industry imposed constraints (e.g. EMV and ITSO) mandating that transactions should complete within a certain time-frame (e.g. 500ms for EMV contactless transactions). The generation of an artificial ambient environment (AAE) using peripherals of the transaction devices has shown positive results when using infrared light as an AAE actuator. In this paper we propose the use of vibration as an alternative AAE actuator. We empirically evaluated the effectiveness of the proposed solution as a PRAD mechanism on an experimental test-bed that we deployed. A total of 36,000 genuine and relay attack transaction pairs were analysed using well-known machine learning algorithms. The results of our analysis indicate that the proposed solution is highly effective.

text: Good vibrations: artificial ambience-based relay attack detection Relay attacks are passive man in the middle attacks, aiming to extend the physical distance of devices involved in a transaction beyond their operating environment, within the restricted time-frame. In the field of smartphones, proposals have been put forward suggesting sensing the natural ambient environment as an effective Proximity and Relay Attack Detection (PRAD) mechanism. However, these proposals are not in compliance with industry imposed constraints (e.g. EMV and ITSO) mandating that transactions should complete within a certain time-frame (e.g. 500ms for EMV contactless transactions). The generation of an artificial ambient environment (AAE) using peripherals of the transaction devices has shown positive results when using infrared light as an AAE actuator. In this paper we propose the use of vibration as an alternative AAE actuator. We empirically evaluated the effectiveness of the proposed solution as a PRAD mechanism on an experimental test-bed that we deployed. A total of 36,000 genuine and relay attack transaction pairs were analysed using well-known machine learning algorithms. The results of our analysis indicate that the proposed solution is highly effective.

year: 2018

title: The Structure of the Oligomerization Domain of Lsr2 from Mycobacterium tuberculosis Reveals a Mechanism for Chromosome Organization and Protection

authors: Summers, Emma Louise

subjects: biology

abstract: Lsr2 is a small DNA-binding protein present in mycobacteria and related actinobacteria that regulates gene expression and influences the organization of bacterial chromatin. Lsr2 is a dimer that binds to AT-rich regions of chromosomal DNA and physically protects DNA from damage by reactive oxygen intermediates (ROI). A recent structure of the C-terminal DNA-binding domain of Lsr2 provides a rationale for its interaction with the minor groove of DNA, its preference for AT-rich tracts, and its similarity to other bacterial nucleoid-associated DNA-binding domains. In contrast, the details of Lsr2 dimerization (and oligomerization) via its N-terminal domain, and the mechanism of Lsr2-mediated chromosomal cross-linking and protection is unknown. We have solved the structure of the N-terminal domain of Lsr2 (N-Lsr2) at 1.73 Å resolution using crystallographic ab initio approaches. The structure shows an intimate dimer of two ß-ß-a motifs with no close homologues in the structural databases. The organization of individual N-Lsr2 dimers in the crystal also reveals a mechanism for oligomerization. Proteolytic removal of three N-terminal residues from Lsr2 results in the formation of an anti-parallel β-sheet between neighboring molecules and the formation of linear chains of N-Lsr2. Oligomerization can be artificially induced using low concentrations of trypsin and the arrangement of N-Lsr2 into long chains is observed in both monoclinic and hexagonal crystallographic space groups. In solution, oligomerization of N-Lsr2 is also observed following treatment with trypsin. A change in chromosomal topology after the addition of trypsin to full-length Lsr2-DNA complexes and protection of DNA towards DNAse digestion can be observed using electron microscopy and electrophoresis. These results suggest a mechanism for oligomerization of Lsr2 via protease-activation leading to chromosome compaction and protection, and concomitant down-regulation of large numbers of genes. This mechanism is likely to be relevant under conditions of stress where cellular proteases are known to be upregulated.

text: The Structure of the Oligomerization Domain of Lsr2 from Mycobacterium tuberculosis Reveals a Mechanism for Chromosome Organization and Protection Lsr2 is a small DNA-binding protein present in mycobacteria and related actinobacteria that regulates gene expression and influences the organization of bacterial chromatin. Lsr2 is a dimer that binds to AT-rich regions of chromosomal DNA and physically protects DNA from damage by reactive oxygen intermediates (ROI). A recent structure of the C-terminal DNA-binding domain of Lsr2 provides a rationale for its interaction with the minor groove of DNA, its preference for AT-rich tracts, and its similarity to other bacterial nucleoid-associated DNA-binding domains. In contrast, the details of Lsr2 dimerization (and oligomerization) via its N-terminal domain, and the mechanism of Lsr2-mediated chromosomal cross-linking and protection is unknown. We have solved the structure of the N-terminal domain of Lsr2 (N-Lsr2) at 1.73 Å resolution using crystallographic ab initio approaches. The structure shows an intimate dimer of two ß-ß-a motifs with no close homologues in the structural databases. The organization of individual N-Lsr2 dimers in the crystal also reveals a mechanism for oligomerization. Proteolytic removal of three N-terminal residues from Lsr2 results in the formation of an anti-parallel β-sheet between neighboring molecules and the formation of linear chains of N-Lsr2. Oligomerization can be artificially induced using low concentrations of trypsin and the arrangement of N-Lsr2 into long chains is observed in both monoclinic and hexagonal crystallographic space groups. In solution, oligomerization of N-Lsr2 is also observed following treatment with trypsin. A change in chromosomal topology after the addition of trypsin to full-length Lsr2-DNA complexes and protection of DNA towards DNAse digestion can be observed using electron microscopy and electrophoresis. These results suggest a mechanism for oligomerization of Lsr2 via protease-activation leading to chromosome compaction and protection, and concomitant down-regulation of large numbers of genes. This mechanism is likely to be relevant under conditions of stress where cellular proteases are known to be upregulated.

year: 2012

title: Mai ngā pouwhirinaki - The experiences of whānau caring for Māori tangata whaiora with traumatic brain injury in the Waikato

authors: Silveira, Maia

subjects: Traumatic brain injury

abstract: In Aotearoa today, Māori have a disproportionate experience of Traumatic Brain Injury (TBI) in the community and in prisons compared to non-Māori. Furthermore, Māori have higher mortality rates following TBI, and are more likely to have a prolonged stay in hospital then be discharged without community support services compared with non-Māori. Currently, many of the post-acute rehabilitation services are located in the Auckland region which causes undue pressure of whānau needs, finances, and work commitments for many whānau and individuals with TBI from the Waikato region. My research focuses on the experiences of whānau navigators experience of caring for Māori tangata whaiora with TBI in the Waikato region. Whānau navigators for this thesis refers to members of the whānau who have familial obligations of care. Within this thesis I consult and engage with whānau about post-acute rehabilitation services. This is a qualitative based research project, which draws upon narrative inquiry, and a Kaupapa Māori research paradigm. Documenting these experiences will provide empirical evidence to highlight the invaluable role whānau have within recovery and the value of whānau support. This research can be used to identify the dynamic needs of whānau and encourage the healthcare system to provide a service that is consistent with Kaupapa Māori health frameworks and practices which at present is non- existent. As a result, the project will help inform the development of a service model within TBI that can better reflect and support the needs of whānau and Māori communities, that is a locally derived practice and more applicable and appropriate for Māori. Mauri ora!

text: Mai ngā pouwhirinaki - The experiences of whānau caring for Māori tangata whaiora with traumatic brain injury in the Waikato In Aotearoa today, Māori have a disproportionate experience of Traumatic Brain Injury (TBI) in the community and in prisons compared to non-Māori. Furthermore, Māori have higher mortality rates following TBI, and are more likely to have a prolonged stay in hospital then be discharged without community support services compared with non-Māori. Currently, many of the post-acute rehabilitation services are located in the Auckland region which causes undue pressure of whānau needs, finances, and work commitments for many whānau and individuals with TBI from the Waikato region. My research focuses on the experiences of whānau navigators experience of caring for Māori tangata whaiora with TBI in the Waikato region. Whānau navigators for this thesis refers to members of the whānau who have familial obligations of care. Within this thesis I consult and engage with whānau about post-acute rehabilitation services. This is a qualitative based research project, which draws upon narrative inquiry, and a Kaupapa Māori research paradigm. Documenting these experiences will provide empirical evidence to highlight the invaluable role whānau have within recovery and the value of whānau support. This research can be used to identify the dynamic needs of whānau and encourage the healthcare system to provide a service that is consistent with Kaupapa Māori health frameworks and practices which at present is non- existent. As a result, the project will help inform the development of a service model within TBI that can better reflect and support the needs of whānau and Māori communities, that is a locally derived practice and more applicable and appropriate for Māori. Mauri ora!

year: 2022