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

Remote Attestation Mechanism for User Centric Smart Cards using Pseudorandom Number Generators

Abstract. User Centric Smart Card Ownership Model (UCOM) gives the freedom of choice of respective applications to the smart card users. The user-centric architecture requires a trusted entity to be present on the smart card to provide security assurance and validation to the requesting application providers. In this paper, we propose the inclusion of a trusted computing platform for smart cards that we refer as the Trusted Environment & Execution Manager (TEM). This is followed by the rationale behind the changes to the traditional smart card architecture to accommodate the remote security assurance and validation mechanism. We propose an attestation protocol that provides an on-demand security validation of a smart card by its respective manufacturer. Finally, the attestation protocol is informally analysed, and its test implementation and performance measurements are presented

Characterising a CPU fault attack model via run-time data analysis

Effective software defences against errors created by fault attacks need to anticipate the probable error response of the target micro-controller. The range of errors and their probability of occurrence is referred to as the Fault Model. Software defences are necessarily a compromise between the impact of an error, its likelihood of occurrence, and the cost of the defence in terms of code size and execution time. In this work we first create a fault insertion system and then use it to demonstrate a technique for precisely triggering and capturing individual error responses within a running micro-controller. This enables a more realistic calibration of a micro-controller's fault model. We apply the system to a representative micro-controller and the results show that error insertion is far more predictable than anticipated, and is consistent over a wide range of experimental tolerances. This observation undermines some widely deployed software defences recommended for fault attack protection

Artificial Ambient Environments for Proximity Critical Applications

In the field of smartphones a number of proposals suggest that sensing the ambient environment can act as an effective anti-relay mechanism. However, existing literature is not compliant with industry standards (e.g. EMV and ITSO) that require transactions to complete within a certain time-frame (e.g. 500ms in the case of EMV contactless payments). In previous work the generation of an artificial ambient environment (AAE), and especially the use of infrared light as an AAE actuator was shown to have high success rate in relay attacks detection. In this paper we investigate the application of infrared as a relay attack detection technique in various scenarios, namely, contactless transactions (mobile payments, transportation ticketing, and physical access control), and continuous Two-Factor Authentication. Operating requirements and architectures are proposed for each scenario, while taking into account industry imposed performance requirements, where applicable. Protocols for integrating the solution into the aforementioned scenarios are being proposed, and formally verified. The impact on the performance is assessed through practical implementation. Proposed protocols are verified using Scyther, a formal mechanical verification tool. Finally, additional scenarios, in which this technique can be applied to prevent relay or other types of attacks, are discussed