Publications

2021

  • [PDF] A. Unterweger, F. Knirsch, C. Brunner, and D. Engel, “Low-risk Privacy-Preserving Electric Vehicle Charging with Payments,” in Workshop on Automotive and Autonomous Vehicle Security (AutoSec), Online, 2021, p. 1–6.
    [Bibtex]
    @inproceedings{Unterweger21a,
    address = {Online},
    author = {Unterweger, Andreas and Knirsch, Fabian and Brunner, Clemens and Engel, Dominik},
    booktitle = {Workshop on Automotive and Autonomous Vehicle Security (AutoSec)},
    pages = {1--6},
    publisher = {The Internet Society},
    title = {Low-risk Privacy-Preserving Electric Vehicle Charging with Payments},
    year = {2021},
    pdf = {https://www.en-trust.at/papers/Unterweger21a.pdf},
    }

2020

  • [PDF] [DOI] F. Knirsch, C. Brunner, A. Unterweger, and D. Engel, “Decentralized and Permission-less Green Energy Certificates with GECKO,” Energy Informatics, vol. 3, iss. 2, p. 1–17, 2020.
    [Bibtex]
    @article{Knirsch20b,
    author = {Knirsch, Fabian and Brunner, Clemens and Unterweger, Andreas and Engel, Dominik},
    journal = {Energy Informatics},
    number = {2},
    pages = {1--17},
    publisher = {Springer International Publishing},
    title = {{Decentralized and Permission-less Green Energy Certificates with GECKO}},
    url = {https://doi.org/10.1186/s42162-020-0104-0},
    doi = {10.1186/s42162-020-0104-0},
    pdf = {https://www.en-trust.at/papers/Knirsch20b.pdf},
    volume = {3},
    year = {2020}
    }
  • [PDF] C. Brunner, F. Knirsch, A. Unterweger, and D. Engel, “A Comparison of Blockchain-based PKI Implementations,” in Proceedings of the 6th International Conference on Information Systems Security and Privacy (ICISSP), Valetta, Malta, 2020, p. 333–340.
    [Bibtex]
    @inproceedings{Brunner20a,
    address = {Valetta, Malta},
    author = {Brunner, Clemens and Knirsch, Fabian and Unterweger, Andreas and Engel, Dominik},
    booktitle = {Proceedings of the 6th International Conference on Information Systems Security and Privacy (ICISSP)},
    pages = {333--340},
    publisher = {SciTePress},
    title = {{A Comparison of Blockchain-based PKI Implementations}},
    year = {2020},
    pdf = {https://www.en-trust.at/papers/Brunner20a.pdf}
    }
  • [PDF] F. Knirsch, A. Unterweger, M. Unterrainer, and D. Engel, “Comparison of the Paillier and ElGamal Cryptosystems for Smart Grid Aggregation Protocols,” in Proceedings of the 6th International Conference on Information Systems Security and Privacy (ICISSP), Valetta, Malta, 2020, p. 232–239.
    [Bibtex]
    @inproceedings{Knirsch20a,
    address = {Valetta, Malta},
    author = {Knirsch, Fabian and Unterweger, Andreas and Unterrainer, Maximilian and Engel, Dominik},
    booktitle = {Proceedings of the 6th International Conference on Information Systems Security and Privacy (ICISSP)},
    pages = {232--239},
    publisher = {SciTePress},
    title = {{Comparison of the Paillier and ElGamal Cryptosystems for Smart Grid Aggregation Protocols}},
    year = {2020},
    pdf = {https://www.en-trust.at/papers/Knirsch20a.pdf}
    }

2019

  • [PDF] [DOI] C. Ferner, G. Eibl, A. Unterweger, S. Burkhart, and S. Wegenkittl, “Pool detection from smart metering data with convolutional neural networks,” Energy Informatics 2019, vol. 2, iss. 1, pp. 1-12, 2019.
    [Bibtex]
    @Article{Ferner19a,
    author = {Cornelia Ferner and Günther Eibl and Andreas Unterweger and Sebastian Burkhart and Stefan Wegenkittl},
    title = {Pool detection from smart metering data with convolutional neural networks},
    journal = {Energy Informatics 2019},
    year = {2019},
    volume = {2},
    pages = {1-12},
    number = {1},
    doi = {10.1186/s42162-019-0097-8},
    pdf = {https://link.springer.com/content/pdf/10.1186%2Fs42162-019-0097-8.pdf},
    publisher = {Springer}
    }
  • [DOI] F. Knirsch, A. Unterweger, and D. Engel, “Implementing a Blockchain from Scratch: Why, How, and What We Learned,” EURASIP Journal on Information Security, vol. 2019, iss. 2, p. 1–14, 2019.
    [Bibtex]
    @article{Knirsch19a,
    abstract = {Blockchains are proposed for many application domains apart from nancial transactions. While there are generic blockchains that can be molded for specific use cases, they often lack a lightweight and easy-to-customize implementation. In this paper, we introduce the core concepts of blockchain technology and investigate a real-world use case from the energy domain, where customers trade portions of their photovoltaic power plant via a blockchain. This does not only involve blockchain technology, but also requires user interaction. Therefore, a fully custom, private and permissioned blockchain is implemented from scratch. We evaluate and motivate the need for blockchain technology within this use case, as well as the desired properties of the system. We then describe the implementation and the insights from our implementation in detail, serving as a guide for others and to show potential opportunities and pitfalls when implementing a blockchain from scratch.},
    author = {Knirsch, Fabian and Unterweger, Andreas and Engel, Dominik},
    journal = {EURASIP Journal on Information Security},
    keywords = {blockchain,implementation,practical insights,private chain},
    title = {{Implementing a Blockchain from Scratch: Why, How, and What We Learned}},
    month = {3},
    year = {2019},
    doi = {10.1186/s13635-019-0085-3},
    pages = {1--14},
    volume = {2019},
    number = {2},
    }
  • [PDF] [DOI] A. Unterweger, S. Taheri-Boshrooyeh, G. Eibl, F. Knirsch, A. Küpçü, and D. Engel, “Understanding Game-Based Privacy Proofs for Energy Consumption Aggregation Protocols,” IEEE Transactions on Smart Grid, vol. 10, iss. 5, p. 5514–5523, 2019.
    [Bibtex]
    @article{Unterweger18b,
    author = {Unterweger, Andreas and Taheri-Boshrooyeh, Sanaz and Eibl, G{\"{u}}nther and Knirsch, Fabian and K{\"{u}}p{\c{c}}{\"{u}}, Alptekin and Engel, Dominik},
    doi = {10.1109/TSG.2018.2883951},
    journal = {IEEE Transactions on Smart Grid},
    number = {5},
    pages = {5514--5523},
    publisher = {IEEE},
    title = {{Understanding Game-Based Privacy Proofs for Energy Consumption Aggregation Protocols}},
    volume = {10},
    pdf = {http://www.en-trust.at/papers/Unterweger18b.pdf},
    year = {2019}
    }

2018

  • [PDF] [DOI] A. Aichhorn, A. Unterweger, D. Engel, and R. Mayrhofer, “Investigating the Impact of Network Security on the Line Current Differential Protection System,” The Journal of Engineering, vol. 2018, iss. 15, p. 1199–1203, 2018.
    [Bibtex]
    @article{Aichhorn18c,
    author = {Aichhorn, Andreas and Unterweger, Andreas and Engel, Dominik and Mayrhofer, Ren{\'{e}}},
    doi = {10.1049/joe.2018.0242},
    journal = {The Journal of Engineering},
    title = {{Investigating the Impact of Network Security on the Line Current Differential Protection System}},
    year = {2018},
    volume = {2018},
    number = {15},
    pages = {1199--1203},
    pdf = {http://www.en-trust.at/papers/Aichhorn18c.pdf},
    }
  • [DOI] A. Aichhorn, B. Etzlinger, A. Unterweger, R. Mayrhofer, and A. Springer, “Design, Implementation, and Evaluation of Secure Communication for Line Current Differential Protection Systems over Packet Switched Networks,” International Journal of Critical Infrastructure Protection, vol. 23, p. 68–78, 2018.
    [Bibtex]
    @article{Aichhorn18b,
    abstract = {In this work we propose a secure communication concept for the protection of critical power supply and distribution infrastructure. Especially, we consider the line current differential protection method for modern smart grid implementations. This protection system operates on critical infrastructure, and it requires a precise time behavior on the communication between devices on both ends of a protected power line. Therefore, the communication has to fulfill deterministic constraints and low-delay requirements and additionally needs to be protected against cyber attacks. Existing systems are often either costly and based on deprecated technology or suffering from maloperations. In order to allow for both, economical and reliable operation, we present the first holistic communication concept capable of using state-of-the-art packet switched networks. Our solution consists of three parts: (i) we develop a list of design requirements for line current differential protection systems communication; (ii) we propose a communication concept obeying these design requirements by combining cryptographical and physical security approaches; and (iii) we evaluate our solution in a practical setup. Our evaluation shows a clock accuracy of 3 µs with a resilience to asymmetric delay attacks down to 8 ns/s. This demonstrates the secure and fault-free operation of a line current differential protection system communicating over a state-of-the-art network.},
    author = {Aichhorn, Andreas and Etzlinger, Bernhard and Unterweger, Andreas and Mayrhofer, Ren{\'{e}} and Springer, Andreas},
    journal = {International Journal of Critical Infrastructure Protection},
    pages = {68--78},
    title = {{Design, Implementation, and Evaluation of Secure Communication for Line Current Differential Protection Systems over Packet Switched Networks}},
    volume = {23},
    year = {2018},
    doi = {10.1016/j.ijcip.2018.06.005},
    }
  • [PDF] A. Aichhorn, A. Unterweger, D. Engel, and R. Mayrhofer, “Investigating the Impact of Network Security on the Line Current Differential Protection System,” in 2018 14th International Conference on Developments in Power System Protection (DPSP), Belfast, UK, 2018, p. to appear.
    [Bibtex]
    @inproceedings{Aichhorn18a,
    abstract = {This paper analyzes the influence of network security measures on the system behavior of a power system protection device. In this particular case, an IP-based Ethernet protection interface of a line current differential protection system is considered. IPsec has previously been proposed to be part of the security concept of the protection interface. Therefore, we conduct a trade-off analysis regarding the influence of IPsec on the protection function and consequently on the system safety. This work shows that the protection function of the relay is not impaired as long as the additional CPU performance for the encryption by the protection relay is available and the necessary bandwidth on the communication channel is provided.},
    address = {Belfast, UK},
    author = {Aichhorn, Andreas and Unterweger, Andreas and Engel, Dominik and Mayrhofer, Ren{\'{e}}},
    booktitle = {2018 14th International Conference on Developments in Power System Protection (DPSP)},
    keywords = {Clock Synchronization,IPsec,Line Current Differential Protection,Network Security,WAN},
    pages = {to appear},
    title = {Investigating the Impact of Network Security on the Line Current Differential Protection System},
    year = {2018},
    pdf={http://www.en-trust.at/papers/Aichhorn18a.pdf},
    }
  • [PDF] [DOI] A. Unterweger, F. Knirsch, C. Leixnering, and D. Engel, “Lessons Learned from Implementing a Privacy-Preserving Smart Contract in Ethereum,” in 2018 9th IFIP International Conference on New Technologies, Mobility and Security (NTMS), Paris, France, 2018.
    [Bibtex]
    @inproceedings{Unterweger18a,
    address = {Paris, France},
    author = {Unterweger, Andreas and Knirsch, Fabian and Leixnering, Christoph and Engel, Dominik},
    booktitle = {2018 9th IFIP International Conference on New Technologies, Mobility and Security (NTMS)},
    publisher = {IEEE},
    title = {{Lessons Learned from Implementing a Privacy-Preserving Smart Contract in Ethereum}},
    year = {2018},
    pdf = {http://www.en-trust.at/papers/Unterweger18a.pdf},
    doi = {10.1109/NTMS.2018.8328739},
    }
  • [PDF] [DOI] S. Burkhart, A. Unterweger, G. Eibl, and D. Engel, “Detecting Swimming Pools in 15-Minute Load Data,” in IEEE International Conference on Trust, Security and Privacy in Computing and Communications 2018, New York, New York, USA, 2018, p. 1641–1655.
    [Bibtex]
    @inproceedings{Burkhart18a,
    address = {New York, New York, USA},
    author = {Burkhart, Sebastian and Unterweger, Andreas and Eibl, Günther and Engel, Dominik},
    booktitle = {{IEEE International Conference on Trust, Security and Privacy in Computing and Communications 2018}},
    month = {8},
    publisher = {{IEEE}},
    title = {{Detecting Swimming Pools in 15-Minute Load Data}},
    year = {2018},
    pdf = {http://www.en-trust.at/papers/Burkhart18a.pdf},
    pages = {1641--1655},
    ISSN ={2324-9013},
    abstract ={The ability to detect appliances in load data highly depends on the resolution of the data. While a lot of related work exists on detecting appliances in second or sub-second granularity load data, in this paper, we detect swimming pools through their filter pumps in load data with the 15-minute granularity prescribed by the European Union for smart meters. We model the filter pump based on exemplary measurements and describe a prototypical algorithm to extract the filter pump's consumption from the aggregated mains signal of a real-world household. We evaluate pool detection performance with different classifiers on a data set with 843 households, where the information on the existence of a swimming pool is available. We achieve 94.8% detection accuracy with a precision of 68.5% with an off-the-shelf classifier. Decreasing the temporal resolution in several steps to 8 hours negatively affects the recall while the precision stays at the same level. We find that these results raise privacy concerns even at the minimum temporal resolution of smart meter data that is legally required in the European Union.},
    keywords={Home appliances;Smart meters;Feature extraction;Hidden Markov models;Frequency measurement;Power demand;privacy;Smart metering},
    doi={10.1109/TrustCom/BigDataSE.2018.00244},
    }
  • [PDF] F. Knirsch, A. Unterweger, K. Karlsson, D. Engel, and S. B. Wicker, “Evaluation of a blockchain-based proof-of-possession implementation,” Center for Secure Energy Informatics, Salzburg University of Applied Sciences, Technical Report 2018-01, 2018-03-23 2018.
    [Bibtex]
    @TechReport{Knirsch18a-t,
    author = {Fabian Knirsch and Andreas Unterweger and Kolbeinn Karlsson and Dominik Engel and Stephen B. Wicker},
    title = {Evaluation of a blockchain-based proof-of-possession implementation},
    institution = {Center for Secure Energy Informatics, Salzburg University of Applied Sciences},
    year = {2018},
    type = {Technical Report},
    number = {2018-01},
    month = mar,
    date = {2018-03-23},
    pdf = {http://www.en-trust.at/papers/Knirsch18a-t.pdf},
    url = {http://www.en-trust.at/papers/Knirsch18a-t.pdf},
    }

2017

  • [PDF] [DOI] F. Knirsch, A. Unterweger, and D. Engel, “Privacy-preserving blockchain-based electric vehicle charging with dynamic tariff decisions,” Computer Science – Research and Development, 2017.
    [Bibtex]
    @Article{Knirsch17c,
    author = {Knirsch, Fabian and Unterweger, Andreas and Engel, Dominik},
    title = {Privacy-preserving blockchain-based electric vehicle charging with dynamic tariff decisions},
    journal = {Computer Science - Research and Development},
    year = {2017},
    month = {9},
    issn = {1865-2042},
    doi = {10.1007/s00450-017-0348-5},
    pdf = {https://link.springer.com/content/pdf/10.1007%2Fs00450-017-0348-5.pdf},
    url = {https://doi.org/10.1007/s00450-017-0348-5},
    }
  • F. Knirsch, A. Unterweger, G. Eibl, and D. Engel, “Privacy-Preserving Smart Grid Tariff Decisions with Block-Chain-Based Smart Contracts,” in Sustainable Cloud and Energy Services: Principles and Practices, W. Rivera, Ed., Springer International Publishing, 2017.
    [Bibtex]
    @InCollection{Knirsch17b,
    author = {Fabian Knirsch and Andreas Unterweger and G\"{u}nther Eibl and Dominik Engel},
    title = {Privacy-Preserving Smart Grid Tariff Decisions with Block-Chain-Based Smart Contracts},
    booktitle = {Sustainable Cloud and Energy Services: Principles and Practices},
    publisher = {Springer International Publishing},
    year = {2017},
    editor = {Wilson Rivera},
    note = {to appear.},
    }
  • [PDF] A. Unterweger, F. Knirsch, C. Leixnering, and D. Engel, “Update: Lessons Learned from Implementing a Privacy-Preserving Smart Contract in Ethereum,” Josef Ressel Center for User-Centric Smart Grid Privacy, Security and Control, Technical Report 2017-03, 2017-11-27 2017.
    [Bibtex]
    @TechReport{Unterweger18a-t,
    author = {Andreas Unterweger and Fabian Knirsch and Christoph Leixnering and Dominik Engel},
    title = {Update: Lessons Learned from Implementing a Privacy-Preserving Smart Contract in Ethereum},
    institution = {Josef Ressel Center for User-Centric Smart Grid Privacy, Security and Control},
    year = {2017},
    type = {Technical Report},
    number = {2017-03},
    month = nov,
    date = {2017-11-27},
    pdf = {http://www.en-trust.at/papers/Unterweger18a-t.pdf},
    url = {http://www.en-trust.at/papers/Unterweger18a-t.pdf},
    }
  • [PDF] F. Knirsch, A. Unterweger, G. Eibl, and D. Engel, “Privacy-Preserving Smart Grid Tariff Decisions with Block-Chain-Based Smart Contracts,” Josef Ressel Center for User-Centric Smart Grid Privacy, Security and Control, Technical Report 2017-01, 2017-05-12 2017.
    [Bibtex]
    @TechReport{Knirsch17b-t,
    author = {Fabian Knirsch and Andreas Unterweger and G\"{u}nther Eibl and Dominik Engel},
    title = {Privacy-Preserving Smart Grid Tariff Decisions with Block-Chain-Based Smart Contracts},
    institution = {Josef Ressel Center for User-Centric Smart Grid Privacy, Security and Control},
    year = {2017},
    type = {Technical Report},
    number = {2017-01},
    month = may,
    date = {2017-05-12},
    pdf = {http://www.en-trust.at/papers/Knirsch17b-t.pdf},
    url = {http://www.en-trust.at/papers/Knirsch17b-t.pdf},
    }

2016

  • [PDF] [DOI] A. Unterweger, F. Knirsch, G. Eibl, and D. Engel, “Privacy-preserving load profile matching for tariff decisions in smart grids,” EURASIP Journal on Information Security, vol. 2016, iss. 1, p. 1–17, 2016.
    [Bibtex]
    @Article{Unterweger16a,
    author = {Unterweger, Andreas and Knirsch, Fabian and Eibl, G{\"u}nther and Engel, Dominik},
    title = {Privacy-preserving load profile matching for tariff decisions in smart grids},
    journal = {{EURASIP} Journal on Information Security},
    year = {2016},
    volume = {2016},
    number = {1},
    pages = {1--17},
    issn = {1687-417X},
    doi = {10.1186/s13635-016-0044-1},
    pdf = {http://jis.eurasipjournals.springeropen.com/track/pdf/10.1186/s13635-016-0044-1},
    }
  • [PDF] [DOI] A. Unterweger and D. Engel, “Lossless Compression of High-Frequency Voltage and Current Data in Smart Grids,” in Proceedings of the 2016 IEEE International Conference on Big Data, 2016, p. 3131–3139.
    [Bibtex]
    @InProceedings{Unterweger16b,
    author = {Unterweger, Andreas and Engel, Dominik},
    title = {{Lossless Compression of High-Frequency Voltage and Current Data in Smart Grids}},
    booktitle = {Proceedings of the 2016 IEEE International Conference on Big Data},
    year = {2016},
    pages = {3131--3139},
    publisher = {IEEE},
    doi = {10.1109/BigData.2016.7840968},
    pdf = {http://www.en-trust.at/papers/Unterweger16b.pdf},
    }

2015

  • [PDF] A. Unterweger, D. Engel, and M. Ringwelski, “The Effect of Data Granularity on Load Data Compression,” Energy Informatics 2015, vol. 9424, p. 69–80, 2015.
    [Bibtex]
    @Article{Unterweger15b,
    author = {Andreas Unterweger and Dominik Engel and Martin Ringwelski},
    title = {The Effect of Data Granularity on Load Data Compression},
    journal = {Energy Informatics 2015},
    year = {2015},
    volume = {9424},
    pages = {69--80},
    editor = {Gottwalt, Sebastian and K\"onig, Lukas and Schmeck, Hartmut},
    pdf = {http://www.en-trust.at/papers/Unterweger15b.pdf},
    publisher = {Springer International Publishing},
    series = {Lecture Notes in Computer Science},
    }
  • [PDF] [DOI] A. Unterweger and D. Engel, “Resumable Load Data Compression in Smart Grids,” IEEE Transactions on Smart Grid, vol. 6, iss. 2, p. 919–929, 2015.
    [Bibtex]
    @Article{Unterweger15a,
    author = {Andreas Unterweger and Dominik Engel},
    title = {Resumable Load Data Compression in Smart Grids},
    journal = {IEEE Transactions on Smart Grid},
    year = {2015},
    volume = {6},
    number = {2},
    pages = {919--929},
    month = {March},
    doi = {10.1109/TSG.2014.2364686},
    pdf = {http://www.en-trust.at/papers/Unterweger15a.pdf},
    publisher = {{IEEE}},
    url = {http://dx.doi.org/10.1109/TSG.2014.2364686},
    }

2013

  • [PDF] S. Auer, A. Bliem, D. Engel, A. Uhl, and A. Unterweger, “Bitstream-based JPEG Encryption in Real-time,” International Journal of Digital Crime and Forensics, vol. 5, iss. 3, p. 1–14, 2013.
    [Bibtex]
    @Article{Auer13a,
    author = {Stefan Auer and Alexander Bliem and Dominik Engel and Andreas Uhl and Andreas Unterweger},
    title = {Bitstream-based {JPEG} Encryption in Real-time},
    journal = {International Journal of Digital Crime and Forensics},
    year = {2013},
    volume = {5},
    number = {3},
    pages = {1--14},
    pdf = {http://www.en-trust.at/papers/Auer13a.pdf},
    }
  • [PDF] [DOI] D. Engel, A. Uhl, and A. Unterweger, “Region of interest signalling for encrypted JPEG images,” in Proceedings of the first ACM workshop on Information hiding and multimedia security (IHMMSEC ’13), Montpellier, France, 2013, p. 165–174.
    [Bibtex]
    @InProceedings{Engel13d,
    author = {Dominik Engel and Andreas Uhl and Andreas Unterweger},
    title = {Region of interest signalling for encrypted JPEG images},
    booktitle = {Proceedings of the first ACM workshop on Information hiding and multimedia security (IHMMSEC '13)},
    year = {2013},
    pages = {165--174},
    address = {Montpellier, France},
    publisher = {ACM},
    acmid = {2482518},
    doi = {10.1145/2482513.2482518},
    isbn = {978-1-4503-2081-8},
    keywords = {JPEG, coordinates, encoding, region of interest, signalling},
    numpages = {10},
    pdf = {http://www.en-trust.at/papers/Engel13d.pdf},
    publisher-address = {New York, NY, USA},
    url = {http://doi.acm.org/10.1145/2482513.2482518},
    }