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: Consistent predator-prey biomass scaling in complex food webs

authors: Perkins, Daniel M.

subjects: Animals

abstract: The ratio of predator-to-prey biomass is a key element of trophic structure that is typically investigated from a food chain perspective, ignoring channels of energy transfer (e.g. omnivory) that may govern community structure. Here, we address this shortcoming by characterising the biomass structure of 141 freshwater, marine and terrestrial food webs, spanning a broad gradient in community biomass. We test whether sub-linear scaling between predator and prey biomass (a potential signal of density-dependent processes) emerges within ecosystem types and across levels of biological organisation. We find a consistent, sub-linear scaling pattern whereby predator biomass scales with the total biomass of their prey with a near ¾-power exponent within food webs - i.e. more prey biomass supports proportionally less predator biomass. Across food webs, a similar sub-linear scaling pattern emerges between total predator biomass and the combined biomass of all prey within a food web. These general patterns in trophic structure are compatible with a systematic form of density dependence that holds among complex feeding interactions across levels of organization, irrespective of ecosystem type.

text: Consistent predator-prey biomass scaling in complex food webs The ratio of predator-to-prey biomass is a key element of trophic structure that is typically investigated from a food chain perspective, ignoring channels of energy transfer (e.g. omnivory) that may govern community structure. Here, we address this shortcoming by characterising the biomass structure of 141 freshwater, marine and terrestrial food webs, spanning a broad gradient in community biomass. We test whether sub-linear scaling between predator and prey biomass (a potential signal of density-dependent processes) emerges within ecosystem types and across levels of biological organisation. We find a consistent, sub-linear scaling pattern whereby predator biomass scales with the total biomass of their prey with a near ¾-power exponent within food webs - i.e. more prey biomass supports proportionally less predator biomass. Across food webs, a similar sub-linear scaling pattern emerges between total predator biomass and the combined biomass of all prey within a food web. These general patterns in trophic structure are compatible with a systematic form of density dependence that holds among complex feeding interactions across levels of organization, irrespective of ecosystem type.

year: 2022-08-25

title: He maimoa i ngā whakatupuranga anamata: Ko te mātauranga taketake o ngā tūpuna me te whakarea tamariki

authors: Greensill, Hineitimoana

subjects: Poipoi tamariki

abstract: Kua āraua ki roto i te reo me ngā pūnaha mātauranga o ngā iwi taketake, ko ngā uara, ko ngā whakapono me ngā rapunga whakaaro e toko ake nei i tērā iwi. Kia whakahoropakitia tēnei ki roto o Aotearoa me Hawai‘i, i te whakaekenga o ō tātou kāinga tupu e ngā taua a te Pākehā me ngā tāmi o ngā tikanga whakawhenumi a te Kāwanantanga o muri, i tauwhatia ai te tuku o te reo Māori me te ‘ōlelo (reo) o Hawai‘i i waenga i ngā whakatupuranga, waihoki ko ngā māramatanga pūmau o roto i ngā reo i tauwhatia ai (Walker, 2004; Blaisdell & Mokuau, 1991). Ahakoa ēnei tauwhatinga, ka pupuri tonu tātou ki ngā karere i mau rā i te reo i roto i ngā ngā pātaka mātauranga a te Māori me nā kānaka (ngā tāngata) o Hawai‘i. Ko te mātauranga taketake, ngā kōrero o nehe me ngā ariā e āraua nei ki ngā tuhituhinga-ā-waha huhua, tae atu ki ngā whakataukī, ngā ‘ōlelo no‘eau, me ngā kīanga rongonui i tāngia hoki ki te pepa (Pukui, 1983). Ko te ia o ēnei momo kōrero tuku-iho taketake nei kei te kōrerotia i roto i ngā whakataukī me ngā ‘ōlelo no‘eau, he mea whakaara anō tēnei mātauranga ki ngā kaupapa whakaora reo ki Aotearoa me Hawai‘i. He momo mātauranga ēnei hei whakaara i a tātou kia mārama rawa ki ngā kano tirohanga o ō tātou tūpuna ki tō rātou ao, waihoki ko ngā hononga maha e paihere nei i a tātou ki ō tātou whanaunga.

Hei whāinga matua e āta arohaehae ana tēnei pepa i ngā momo tuhituhinga-ā-waha nei, arā ko te ‘ōlelo no‘eau me te whakataukī, kia tīroua ake ngā karere e hāngai ana ki ngā tamariki a te Māori rātou ko ngā kānaka o Hawai‘i me ngā pānga ki ngā mahi whakatupu tamariki o mua. Ka toro tēnei tuhinga ki te whakataukī me te ‘ōlelo no‘eau ki te whakapuaki i te mātauranga i mahue mai i ngā tūpuna hei rei arataki mā tātou ngā iwi taketake me ō tātou wheako tonu o nāianei.

text: He maimoa i ngā whakatupuranga anamata: Ko te mātauranga taketake o ngā tūpuna me te whakarea tamariki Kua āraua ki roto i te reo me ngā pūnaha mātauranga o ngā iwi taketake, ko ngā uara, ko ngā whakapono me ngā rapunga whakaaro e toko ake nei i tērā iwi. Kia whakahoropakitia tēnei ki roto o Aotearoa me Hawai‘i, i te whakaekenga o ō tātou kāinga tupu e ngā taua a te Pākehā me ngā tāmi o ngā tikanga whakawhenumi a te Kāwanantanga o muri, i tauwhatia ai te tuku o te reo Māori me te ‘ōlelo (reo) o Hawai‘i i waenga i ngā whakatupuranga, waihoki ko ngā māramatanga pūmau o roto i ngā reo i tauwhatia ai (Walker, 2004; Blaisdell & Mokuau, 1991). Ahakoa ēnei tauwhatinga, ka pupuri tonu tātou ki ngā karere i mau rā i te reo i roto i ngā ngā pātaka mātauranga a te Māori me nā kānaka (ngā tāngata) o Hawai‘i. Ko te mātauranga taketake, ngā kōrero o nehe me ngā ariā e āraua nei ki ngā tuhituhinga-ā-waha huhua, tae atu ki ngā whakataukī, ngā ‘ōlelo no‘eau, me ngā kīanga rongonui i tāngia hoki ki te pepa (Pukui, 1983). Ko te ia o ēnei momo kōrero tuku-iho taketake nei kei te kōrerotia i roto i ngā whakataukī me ngā ‘ōlelo no‘eau, he mea whakaara anō tēnei mātauranga ki ngā kaupapa whakaora reo ki Aotearoa me Hawai‘i. He momo mātauranga ēnei hei whakaara i a tātou kia mārama rawa ki ngā kano tirohanga o ō tātou tūpuna ki tō rātou ao, waihoki ko ngā hononga maha e paihere nei i a tātou ki ō tātou whanaunga.

Hei whāinga matua e āta arohaehae ana tēnei pepa i ngā momo tuhituhinga-ā-waha nei, arā ko te ‘ōlelo no‘eau me te whakataukī, kia tīroua ake ngā karere e hāngai ana ki ngā tamariki a te Māori rātou ko ngā kānaka o Hawai‘i me ngā pānga ki ngā mahi whakatupu tamariki o mua. Ka toro tēnei tuhinga ki te whakataukī me te ‘ōlelo no‘eau ki te whakapuaki i te mātauranga i mahue mai i ngā tūpuna hei rei arataki mā tātou ngā iwi taketake me ō tātou wheako tonu o nāianei.

year: 2017