title: Remote attestation mechanism for embedded devices based on physical unclonable functions

authors: Akram, Raja Naeem

abstract: Remote attestation mechanisms are well studied in the high-end computing environments; however, the same is not true for embedded devices-especially for smart cards. With ever changing landscape of smart card technology and advancements towards a true multi-application platform, verifying the current state of the smart card is significant to the overall security of such proposals. The initiatives proposed by GlobalPlatform Consumer Centric Model (GP-CCM) and User Centric Smart Card Ownership Model (UCOM) enables a user to download any application as she desire-depending upon the authorisation of the application provider. Before an application provider issues an application to a smart card, verifying the current state of the smart card is crucial to the security of the respective application. In this paper, we analyse the rationale behind the remote attestation mechanism for smart cards, and the fundamental features that such a mechanism should possess. We also study the applicability of Physical Unclonable Functions (PUFs) for the remote attestation mechanism and propose two algorithms to achieve the stated features of remote attestation. The proposed algorithms are implemented in a test environment to evaluate their performance. © 2013 The authors and IOS Press. All rights reserved.

text: Remote attestation mechanism for embedded devices based on physical unclonable functions Remote attestation mechanisms are well studied in the high-end computing environments; however, the same is not true for embedded devices-especially for smart cards. With ever changing landscape of smart card technology and advancements towards a true multi-application platform, verifying the current state of the smart card is significant to the overall security of such proposals. The initiatives proposed by GlobalPlatform Consumer Centric Model (GP-CCM) and User Centric Smart Card Ownership Model (UCOM) enables a user to download any application as she desire-depending upon the authorisation of the application provider. Before an application provider issues an application to a smart card, verifying the current state of the smart card is crucial to the security of the respective application. In this paper, we analyse the rationale behind the remote attestation mechanism for smart cards, and the fundamental features that such a mechanism should possess. We also study the applicability of Physical Unclonable Functions (PUFs) for the remote attestation mechanism and propose two algorithms to achieve the stated features of remote attestation. The proposed algorithms are implemented in a test environment to evaluate their performance. © 2013 The authors and IOS Press. All rights reserved.

year: 2013

title: Techniques for low coherence pulsed Doppler lidar

authors: Dorrington, Adrian A.

abstract: Wind shear and clear air turbulence are atmospheric phenomena that pose a hazard to aircraft and their passengers. In the past, these phenomena have caused injuries and the occasional death. The ability of a lidar system to make wind speed measurements and detect wind shear and turbulence has been known for some time. However, lidar systems are still not commercially viable as early warning systems in aircraft and at airports. The main reason is the expense and bulk of the single frequency injection locked lasers currently used. These are required to ensure coherence is maintained between the reference and measurement beams over long pathlength differences. 

In order to reduce the cost and size of lidar systems, we have developed new lidar design philosophies based on using components that are cheaper and smaller. Two different techniques are presented in this thesis, one to eliminate the requirement for a highly coherent laser source, and the other provides a method to generate a frequency offset that is an alternative to the currently favoured acousto-optic modulator. 

The first approach presented is a design in which a sample of the transmitted pulse is stored in a fibre optic ring resonator of pathlength longer than the pulse. Each time the pulse circulates the storage loop a fraction is split off and used as the reference beam. Because this reference beam has travelled an equivalent distance to the measurements beam, the coherence requirements are relaxed significantly allowing the use of a much cheaper and smaller low coherence source. 

In the second method presented, a frequency offset is generated without the use of the currently favoured and relatively expensive acousto-optic modulator. This method utilises a quadrature beam combiner and radio frequency quadrature modulator techniques. Configured as a single sideband (SSB) modulator, two balanced mixers produce double sideband signals in which one sideband is π out-of-phase. When combined, one sideband cancels leaving a single sideband output containing the baseband Doppler signal shifted up the RF spectrum by a predetermined offset. This is implemented in both electronic and semi-optical configurations. 

Concept validation experiments have been performed for both techniques. Using the reference beam storage loop, the velocity of a rotating mirror was measured at several simulated ranges. Successful optical mixing between the stored reference and the delayed measurement beams has been demonstrated. Utilising the SSB offset generation method, the velocity of a piezo mounted mirror has also been successfully measured, after an offset was applied with the new techniques. The results obtained show that both concepts are viable, and that these techniques could be applied in a new lidar design philosophy resulting in significant benefits with respect to complexity, cost, size, weight, and power consumption.

text: Techniques for low coherence pulsed Doppler lidar Wind shear and clear air turbulence are atmospheric phenomena that pose a hazard to aircraft and their passengers. In the past, these phenomena have caused injuries and the occasional death. The ability of a lidar system to make wind speed measurements and detect wind shear and turbulence has been known for some time. However, lidar systems are still not commercially viable as early warning systems in aircraft and at airports. The main reason is the expense and bulk of the single frequency injection locked lasers currently used. These are required to ensure coherence is maintained between the reference and measurement beams over long pathlength differences. 

In order to reduce the cost and size of lidar systems, we have developed new lidar design philosophies based on using components that are cheaper and smaller. Two different techniques are presented in this thesis, one to eliminate the requirement for a highly coherent laser source, and the other provides a method to generate a frequency offset that is an alternative to the currently favoured acousto-optic modulator. 

The first approach presented is a design in which a sample of the transmitted pulse is stored in a fibre optic ring resonator of pathlength longer than the pulse. Each time the pulse circulates the storage loop a fraction is split off and used as the reference beam. Because this reference beam has travelled an equivalent distance to the measurements beam, the coherence requirements are relaxed significantly allowing the use of a much cheaper and smaller low coherence source. 

In the second method presented, a frequency offset is generated without the use of the currently favoured and relatively expensive acousto-optic modulator. This method utilises a quadrature beam combiner and radio frequency quadrature modulator techniques. Configured as a single sideband (SSB) modulator, two balanced mixers produce double sideband signals in which one sideband is π out-of-phase. When combined, one sideband cancels leaving a single sideband output containing the baseband Doppler signal shifted up the RF spectrum by a predetermined offset. This is implemented in both electronic and semi-optical configurations. 

Concept validation experiments have been performed for both techniques. Using the reference beam storage loop, the velocity of a rotating mirror was measured at several simulated ranges. Successful optical mixing between the stored reference and the delayed measurement beams has been demonstrated. Utilising the SSB offset generation method, the velocity of a piezo mounted mirror has also been successfully measured, after an offset was applied with the new techniques. The results obtained show that both concepts are viable, and that these techniques could be applied in a new lidar design philosophy resulting in significant benefits with respect to complexity, cost, size, weight, and power consumption.

year: 2000

title: Te mōhiotangaora: Within the knowing healing begins

authors: Witehira, Tracey Moana

abstract: This thesis investigates the intersection of the colonized self and the Māori self, examining how these dual identities coexist within the same physical, mental, and spiritual space. Grounded in Māori ontology and wellness (Durie, 1998), the study uses an interdisciplinary approach that combines academic analysis, creative writing, pūrākau  (Lee, 2009), journal reflections, and artistic practice to explore two distinct ways of knowing that operate within this duality.
In this academic study, the colonized self is defined as a Māori woman shaped and constrained by the effects of colonization (Gemmell, 2013: Mikaere, 2003). Conversely, the Māori self represents the awakened Wahine Māori who has embraced mātauranga  Māori. She actively learns, embodies, practices, and lives Māori values and traditions as part of her everyday life. However, the Wahine Māori is not entirely free from the ongoing impacts of colonization, given the long history of conflict between Māori and European peoples in Aotearoa.  The colonization of New Zealand, marked by the signing of the Treaty of Waitangi in 1840, resulted in the systematic loss of cultural markers central to Māori identity (Jackson, 1998, 1995; Walker, 1990). Furthermore, government policies have contributed to the marginalization of Māori culture in areas such as family, education, religion, and loss of language (Pihama, 2001; Smith, 1999).
Through this creative practice research, the practice of raranga whatu is explored using both traditional and contemporary techniques, contributing to the development of mātauranga Māori art forms (Campbell, 2019; Smith, 2019). This study examines how the process of weaving supports one woman’s journey of reclaiming and empowering her Indigenous identity. Whatu raranga serves as a transformative practice, embodying the duality of the self within a uniquely Māori space of being. Within a Kaupapa Māori framework, the process of restoring cultural connections has supported the reawakening of Mana Wahine identity and the reclamation of Māori spaces, as recognized and embodied by kairaranga  (Campbell, 2019; Pere, 1991; H. Smith, 2019; Yates-Smith, 1980).

text: Te mōhiotangaora: Within the knowing healing begins This thesis investigates the intersection of the colonized self and the Māori self, examining how these dual identities coexist within the same physical, mental, and spiritual space. Grounded in Māori ontology and wellness (Durie, 1998), the study uses an interdisciplinary approach that combines academic analysis, creative writing, pūrākau  (Lee, 2009), journal reflections, and artistic practice to explore two distinct ways of knowing that operate within this duality.
In this academic study, the colonized self is defined as a Māori woman shaped and constrained by the effects of colonization (Gemmell, 2013: Mikaere, 2003). Conversely, the Māori self represents the awakened Wahine Māori who has embraced mātauranga  Māori. She actively learns, embodies, practices, and lives Māori values and traditions as part of her everyday life. However, the Wahine Māori is not entirely free from the ongoing impacts of colonization, given the long history of conflict between Māori and European peoples in Aotearoa.  The colonization of New Zealand, marked by the signing of the Treaty of Waitangi in 1840, resulted in the systematic loss of cultural markers central to Māori identity (Jackson, 1998, 1995; Walker, 1990). Furthermore, government policies have contributed to the marginalization of Māori culture in areas such as family, education, religion, and loss of language (Pihama, 2001; Smith, 1999).
Through this creative practice research, the practice of raranga whatu is explored using both traditional and contemporary techniques, contributing to the development of mātauranga Māori art forms (Campbell, 2019; Smith, 2019). This study examines how the process of weaving supports one woman’s journey of reclaiming and empowering her Indigenous identity. Whatu raranga serves as a transformative practice, embodying the duality of the self within a uniquely Māori space of being. Within a Kaupapa Māori framework, the process of restoring cultural connections has supported the reawakening of Mana Wahine identity and the reclamation of Māori spaces, as recognized and embodied by kairaranga  (Campbell, 2019; Pere, 1991; H. Smith, 2019; Yates-Smith, 1980).

year: 2025-01