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Auflistung nach Autor:in "Sedlmeir, Johannes"

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  • Zeitschriftenartikel
    A Systematic Review of Identity and Access Management Requirements in Enterprises and Potential Contributions of Self-Sovereign Identity
    (Business & Information Systems Engineering: Vol. 66, No. 4, 2024) Glöckler, Jana; Sedlmeir, Johannes; Frank, Muriel; Fridgen, Gilbert
    Digital identity and access management (IAM) poses significant challenges for companies. Cyberattacks and resulting data breaches frequently have their root cause in enterprises’ IAM systems. During the COVID-19 pandemic, issues with the remote authentication of employees working from home highlighted the need for better IAM solutions. Using a design science research approach, the paper reviews the requirements for IAM systems from an enterprise perspective and identifies the potential benefits of self-sovereign identity (SSI) – an emerging, passwordless paradigm in identity management that provides end users with cryptographic attestations stored in digital wallet apps. To do so, this paper first conducts a systematic literature review followed by an interview study and categorizes IAM system requirements according to security and compliance, operability, technology, and user aspects. In a second step, it presents an SSI-based prototype for IAM, whose suitability for addressing IAM challenges was assessed by twelve domain experts. The results suggest that the SSI-based authentication of employees can address requirements in each of the four IAM requirement categories. SSI can specifically improve manageability and usability aspects and help implement acknowledged best practices such as the principle of least privilege. Nonetheless, the findings also reveal that SSI is not a silver bullet for all of the challenges that today’s complex IAM systems face.
  • Zeitschriftenartikel
    Ein Blick auf aktuelle Entwicklungen bei Blockchains und deren Auswirkungen auf den Energieverbrauch
    (Informatik Spektrum: Vol. 43, No. 6, 2020) Sedlmeir, Johannes; Buhl, Hans Ulrich; Fridgen, Gilbert; Keller, Robert
    Der enorme Stromverbrauch von Bitcoin hat dazu geführt, dass in Wissenschaft und Praxis oft eher undifferenziert Diskussionen über die Nachhaltigkeit von Blockchain- bzw. Distributed-Ledger-Technologie allgemein geführt werden. Allerdings ist die Blockchain-Technologie bereits heute alles andere als homogen – nicht nur hinsichtlich ihrer Anwendungen, die mittlerweile weit über Kryptowährungen hinaus in Wirtschaft und öffentlichen Sektor reichen, sondern auch bezüglich ihrer technischen Charakteristika und insbesondere ihres Stromverbrauchs. Dieser Beitrag fasst den Status quo des Stromverbrauchs verschiedener Implementierungen von Blockchain-Technologie zusammen und geht dabei besonders auf das kürzlich erfolgte Bitcoin Halving sowie sogenannte ZK-Rollups ein. Wir argumentieren, dass Bitcoin und andere Proof-of-Work-Blockchains zwar in der Tat sehr viel Strom verbrauchen, aber bereits heute alternative Blockchain-Lösungen mit deutlich geringerem Stromverbrauch verfügbar sind und weitere vielversprechende Konzepte erprobt werden, die gerade den Stromverbrauch von großen Blockchain-Netzwerken in naher Zukunft noch einmal deutlich senken könnten. Daraus schließen wir, dass die Kritik am Stromverbrauch von Bitcoin zwar legitim ist, jedoch daraus nicht eine Energieproblematik von Blockchain-Technologie generell abgeleitet werden darf. In vielen Fällen, in denen mithilfe von energieeffizienteren Blockchain-Varianten Prozesse digitalisiert oder verbessert werden können, darf sogar per Saldo durchaus mit Energieeinsparungen gerechnet werden. The enormous power consumption of Bitcoin has led to undifferentiated discussions in science and practice about the sustainability of blockchain and distributed ledger technology in general. However, blockchain technology is far from homogeneous—not only with regard to its applications, which now go far beyond cryptocurrencies and have reached businesses and the public sector, but also with regard to its technical characteristics and, in particular, its power consumption. This paper summarizes the status quo of the power consumption of various implementations of blockchain technology, with special emphasis on the recent ‘‘Bitcoin Halving’’ and so-called ‘‘zk-rollups’’. We argue that although Bitcoin and other proof-of-work blockchains do indeed consume a lot of power, alternative blockchain solutions with significantly lower power consumption are already available today, and new promising concepts are being tested that could further reduce in particulary the power consumption of large blockchain networks in the near future. From this we conclude that although the criticism of Bitcoin’s power consumption is legitimate, it should not be used to derive an energy problem of blockchain technology in general. In many cases in which processes can be digitized or improved with the help of more energy-efficient blockchain variants, one can even expect net energy savings.
  • Zeitschriftenartikel
    Digital Identities and Verifiable Credentials
    (Business & Information Systems Engineering: Vol. 63, No. 5, 2021) Sedlmeir, Johannes; Smethurst, Reilly; Rieger, Alexander; Fridgen, Gilbert
  • Zeitschriftenartikel
    The Energy Consumption of Blockchain Technology: Beyond Myth
    (Business & Information Systems Engineering: Vol. 62, No. 6, 2020) Sedlmeir, Johannes; Buhl, Hans Ulrich; Fridgen, Gilbert; Keller, Robert
    When talking about blockchain technology in academia, business, and society, frequently generalizations are still heared about its – supposedly inherent – enormous energy consumption. This perception inevitably raises concerns about the further adoption of blockchain technology, a fact that inhibits rapid uptake of what is widely considered to be a groundbreaking and disruptive innovation. However, blockchain technology is far from homogeneous, meaning that blanket statements about its energy consumption should be reviewed with care. The article is meant to bring clarity to the topic in a holistic fashion, looking beyond claims regarding the energy consumption of Bitcoin, which have, so far, dominated the discussion.