Philipp Miedl


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Miedl

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Philipp

ORCID

0000-0002-5828-8532

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2016 - 201952020 - 20216
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Publications 1 - 10 of 11
  • Frequency Scaling as a Security Threat on Multicore Systems
    Item type: Conference Paper
    Miedl, Philipp; He, Xiaoxi; Meyer, Matthias; et al. (2018)
    IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
    Most modern processors use Dynamic Voltage and Frequency Scaling (DVFS) for power management. DVFS allows to optimize power consumption by scaling voltage and frequency depending on performance demand. Previous research has indicated that this frequency scaling might pose a security threat in the form of a covert channel, which could leak sensitive information. However, an analysis able to determine whether DVFS is a serious security issue is still missing. In this paper, we conduct a detailed analysis of the threat potential of a DVFS-based covert channel. We investigate two multicore platforms representative of modern laptops and hand-held devices. Furthermore, we develop a channel model to determine an upper bound to the channel capacity, which is in the order of 1 bit per channel use. Last, we perform an experimental analysis using a novel transceiver implementation. The neural network based receiver yields packet error rates between 1% and 8% at average throughputs of up to 1.83 and 1.20 bits per second for platforms representative of laptops and hand-held devices, respectively. Considering the well-known small message criterion, our results show that a relevant covert channel can be established by exploiting the behaviour of computing systems with DVFS.
  • Increased reproducibility and comparability of data leak evaluations using ExOT
    Item type: Conference Paper
    Miedl, Philipp; Klopott, Bruno; Thiele, Lothar (2020)
    2020 Design, Automation & Test in Europe Conference & Exhibition (DATE 2020)
    As computing systems are increasingly shared among different users or application domains, researchers have intensified their efforts to detect possible data leaks. In particular, many investigations highlight the vulnerability of systems w. r. t. covert and side channel attacks. However, the effort required to reproduce and compare different results has proven to be high. Therefore, we present a novel methodology for covert channel evaluation. In addition, we introduce the Experiment Orchestration Toolkit ExOT, which provides software tools to efficiently execute the methodology. Our methodology ensures that the covert channel analysis yields expressive results that can be reproduced and allow the comparison of the threat potential of different data leaks. ExOT is a software bundle that consists of easy to extend C++ libraries and Python packages. These libraries and packages provide tools for the generation and execution of experiments, as well as the analysis of the experimental data. Therefore, ExOT decreases the engineering effort needed to execute our novel methodology. We verify these claims with an extensive evaluation of four different covert channels on an Intel Haswell and an ARMv8 based platform. In our evaluation, we derive capacity bounds and show achievable throughputs to compare the threat potential of these different covert channels.
  • We know what you're doing! Application detection using thermal data
    Item type: Journal Article
    Miedl, Philipp; Ahmed, Rehan; Thiele, Lothar (2021)
    Leibniz Transactions on Embedded Systems
    Modern mobile and embedded devices have high computing power which allows them to be used for multiple purposes. Therefore, applications with low security restrictions may execute on the same device as applications handling highly sensitive information. In such a setup, a security risk occurs if it is possible that an application uses system characteristics to gather information about another application on the same device. In this work, we present a method to leak sensitive runtime information by just using temperature sensor readings of a mobile device. We employ a Convolutional-Neural-Network, Long Short-Term Memory units and subsequent label sequence processing to identify the sequence of executed applications over time. To test our hypothesis we collect data from two state-of-the-art smartphones and real user usage patterns. We show an extensive evaluation using laboratory data, where we achieve labelling accuracies up to 90% and negligible timing error. Based on our analysis we state that the thermal information can be used to compromise sensitive user data and increase the vulnerability of mobile devices. A study based on data collected outside of the laboratory opens up various future directions for research.
  • Frequency Scaling as a Security Threat on Multicore Systems
    Item type: Conference Poster
    Miedl, Philipp; He, Xiaoxi; Meyer, Matthias; et al. (2018)
  • On the Capacity of Thermal Covert Channels in Multicores
    Item type: Conference Paper
    Bartolini, Davide B.; Miedl, Philipp; Thiele, Lothar (2016)
    EuroSys '16 Proceedings of the Eleventh European Conference on Computer Systems
  • Threat potential assessment of power management related data leaks
    Item type: Doctoral Thesis
    Miedl, Philipp (2020)
    Modern computing systems rely heavily on power management to accomplish two main tasks: (i) efficient use of the available energy resources, (ii) prevention of the device from suffering damage by exceeding its physical limitation. The power management system tries to achieve these two goals by enacting policies that, at the same time, aim to reduce the performance penalty experienced by the user. To achieve this, the power management uses the system utilisation and device characteristics, such as thermal behaviour, power dissipation or operating frequency. Therefore, there is a link between the execution of applications and these power management related device characteristics. Due to the high computing power available, devices are increasingly shared among multiple application domains or multiple users. For example, a smartphone might be used for private and business applications, or multiple users might reside on the same physical server. To guarantee the security of confidential data in such a shared setup, data and application-dependent information must be confined. Confidential information must not be revealed to third parties without the consent of the data owner. Therefore, researchers have increased their efforts to develop security frameworks to enforce this confinement, for example, by using virtualisation techniques. However, data leaks based on shared resources pose a major threat towards such a security framework. As the behaviour of the power management system influences all application or user domains on a device, the power management system is regarded as a potential source for such data leaks. While the research community has increased their focus on side and covert channel attacks, several challenges related to these attacks remain. For instance, executing a data leak analysis in a reproducible, comparable and exhaustive fashion requires substantial investments of time and engineering resources. This is due to the nature of data leaks being caused by the interplay of different system components, which makes it difficult to detect, reproduce and analyse them on different devices. Therefore, a methodology is needed to support reproducible, comparable and expressive analysis results and tools that help to reduce the effort needed to execute an exhaustive data leak analysis. Furthermore, while many data leaks have been discovered in recent years, little attention has been given to security implications of the power management in multicore systems. In this thesis, we attempt to solve these challenges and investigate the threat potential of power management related data leaks in multicore systems. We summarise the main contributions as follows: * We define a novel methodology to analyse covert channels exhaustively. This methodology helps to derive expressive metrics for assessing the threat potential of covert channels. Furthermore, we are the first to provide a measurement automation toolkit which implements the methodology. Due to its design, this toolkit allows us to apply the methodology to a variety of target platforms. * We outline a novel procedure to derive upper channel capacity bounds for continuous covert channels. Furthermore, compared to previous work, we improve throughputs of thermal covert channels in multicore systems by applying a more sophisticated communication scheme. * We are the first to analyse the power covert channel in current multicore systems exhaustively. In addition, we illustrate the derivation of upper channel capacity bounds for such discrete covert channels. * We present a communication model and provide an in-depth analysis of the frequency covert channel. Moreover, we are the first to use a Recurrent Neural Network (RNN) for symbol decoding in a frequency covert channel setup. * We establish a novel side channel attack based on system temperatures to extract runtime information from mobile devices. This side channel attack uses Neural Network time-sequence labelling models. Furthermore, we present a method for thermal data augmentation to reduce the necessary measurement effort to generate a suitable training data set. The presented methods and findings are based on extensive experimental evaluations. We publish the tools used in these experiments and the acquired data along with this thesis, to support comparability and reproducibility of our results.
  • The security risks of power measurements in multicores
    Item type: Conference Paper
    Miedl, Philipp; Thiele, Lothar (2018)
    Proceedings of the 33rd Annual ACM Symposium on Applied Computing
    Two of the main goals of power management in modern multicore processors are reducing the average power dissipation and delivering the maximum performance up to the physical limits of the system, when demanded. To achieve these goals, hardware manufacturers and operating system providers include sophisticated power and performance management systems, which require detailed information about the current processor state. For example, Intel processors offer the possibility to measure the power dissipation of the processor. In this work, we are evaluating whether such power measurements can be used to establish a covert channel between two isolated applications on the same system; the power covert channel. We present a detailed theoretical and experimental evaluation of the power covert channel on two platforms based on Intel processors. Our theoretical analysis is based on detailed modelling and allows us to derive a channel capacity bound for each platform. Moreover, we conduct an extensive experimental study under controlled, yet realistic, conditions. Our study shows, that the platform dependent channel capacities are in the order of 2000 bps and that it is possible to achieve throughputs of up to 1000 bps with a bit error probability of less than 15%, using a simple implementation. This illustrates the potential of leaking sensitive information and breaking a systems security framework using a covert channel based on power measurements.
  • Errata: “Increased reproducibility and comparability of data leak evaluations using ExOT”
    Item type: Other Conference Item
    Miedl, Philipp; Klopott, Bruno; Thiele, Lothar (2020)
  • Increased reproducibility and comparability of data leak evaluations using ExOT
    Item type: Conference Paper
    Miedl, Philipp; Klopott, Bruno; Thiele, Lothar (2020)
    2020 Design, Automation and Test in Europe Conference and Exhibition (DATE)
    As computing systems are increasingly shared among different users or application domains, researchers have intensified their efforts to detect possible data leaks. In particular, many investigations highlight the vulnerability of systems w.r.t. covert and side channel attacks. However, the effort required to reproduce and compare different results has proven to be high. Therefore, we present a novel methodology for covert channel evaluation. In addition, we introduce the Experiment Orchestration Toolkit ExOT, which provides software tools to efficiently execute the methodology.Our methodology ensures that the covert channel analysis yields expressive results that can be reproduced and allow the comparison of the threat potential of different data leaks. ExOT is a software bundle that consists of easy to extend C++ libraries and Python packages. These libraries and packages provide tools for the generation and execution of experiments, as well as the analysis of the experimental data. Therefore, ExOT decreases the engineering effort needed to execute our novel methodology. We verify these claims with an extensive evaluation of four different covert channels on an Intel Haswell and an ARMv8 based platform. In our evaluation, we derive capacity bounds and show achievable throughputs to compare the threat potential of these different covert channels. © 2020 EDAA.
Publications 1 - 10 of 11