Comparing Successful DLT Consortia: A Lifecycle Perspective

In 2021, enterprise distributed ledger technology has evolved beyond the proof-of-concept stage. It is now providing business value to large consortia in several successful and well documented case studies. Nevertheless, other consortia and initiatives are stuck in early stages of consortium formation or conceptualization. They stand to benefit from lessons learned by successful consortia, but an in-depth comparison has not yet been conducted. Thus, this study performs the first methodological comparison of large DLT consortia that have launched a product. Based on the temporal evolution of these consortia, a lifecycle with 4 stages and 12 sub-phases is developed to provide further guidance for early-stage consortia. The results show how 9 pioneer consortia have successfully integrated novel DLT into existing processes, but also point out challenges faced on the way

Secure Information Sharing with Distributed Ledgers

In 2009, blockchain technology was first introduced as the supporting database technology for digital currencies. Since then, more advanced derivations of the technology have been developed under the broader term Distributed Ledgers, with improved scalability and support for general-purpose application logic. As a distributed database, they are able to support interorganizational information sharing while assuring desirable information security attributes like non-repudiation, auditability and transparency. Based on these characteristics, researchers and practitioners alike have begun to identify a plethora of disruptive use cases for Distributed Ledgers in existing application domains. While these use cases are promising significant efficiency improvements and cost reductions, practical adoption has been slow in the past years. This dissertation focuses on improving three aspects contributing to slow adoption. First, it attempts to identify application areas and substantiated use cases where Distributed Ledgers can considerably advance the security of information sharing. Second, it considers the security aspects of the technology itself, identifying threats to practical applications and detection approaches for these threats. And third, it investigates success factors for successful interorganizational collaborations using Distributed Ledgers

Digging for Quality Management in Production Systems: A Solution Space for Blockchain Collaborations

Quality management (QM) and efficient information sharing among value chain partners have been important IS research topics for decades. Today, IS researchers and practitioners hope to overcome various information inefficiencies in complex supply chains using blockchain approaches. Additionally, future traceability regulations increase companies’ interest in innovative blockchain-based enterprise solutions. We identified several factors that could hinder BC adoption, due to a lack of standards. This paper sheds profound light on organizational and technical aspects of blockchain enterprise applications to support future collaboration initiatives. Furthermore, it develops a terminology that researchers and practitioners can reuse. A case study describes several quality-related objects and events that characterize multiple dimensions and traceability types. Based on these findings, we provide a set of design principles to assist future design features. Finally, this paper provides a holistic orientation and implications for researchers and practitioners moving forwards

Detecting Blockchain Security Threats

In many organizations, permissioned blockchain networks are currently transitioning from a proof-of-concept stage to production use. A crucial part of this transition is ensuring awareness of potential threats to network operations. Due to the plethora of software components involved in distributed ledgers, threats may be difficult or impossible to detect without a structured monitoring approach. To this end, we conduct a survey of attacks on permissioned blockchains and develop a set of threat indicators. To gather these indicators, a data processing pipeline is proposed to aggregate log information from relevant blockchain components, enriched with data from external sources. To evaluate the feasibility of monitoring current blockchain frameworks, we determine relevant data sources in Hyperledger Fabric. Our results show that the required data is mostly available, but also highlight significant improvement potential with regard to threat intelligence, chaincode scanners and built-in metrics

A Distributed Ledger Approach to Digital Twin Secure Data Sharing

The Digital Twin refers to a digital representation of any real-world counterpart allowing its management (from simple monitoring to autonomy). At the core of the concept lies the inclusion of the entire asset lifecycle. To enable all lifecycle parties to partake, the Digital Twin should provide a sharable data base. Thereby, integrity and confidentiality issues are pressing, turning security into a major requirement. However, given that the Digital Twin paradigm is still at an early stage, most works do not consider security yet. Distributed ledgers provide a novel technology for multi-party data sharing that emphasizes security features such as integrity. For this reason, we examine the applicability of distributed ledgers to secure Digital Twin data sharing. We contribute to current literature by identifying requirements for Digital Twin data sharing in order to overcome current infrastructural challenges. We furthermore propose a framework for secure Digital Twin data sharing based on Distributed Ledger Technology. A conclusive use case demonstrates requirements fulfillment and is followed by a critical discussion proposing avenues for future work

BISCUIT - Blockchain Security Incident Reporting based on Human Observations

Security incidents in blockchain-based systems are frequent nowadays, which calls for more structured efforts in incident reporting and response. To improve the current status quo of reporting incidents on blogs and social media, we propose a decentralized incident reporting and discussion system. Our approach guides users (security novices) towards a classification of their observations using a tiered taxonomy of blockchain incidents. Questions based on previous incidents interactively support the classification. Post submission a security incident response committee then discusses these observations on our decentralized platform to decide on an appropriate response. For evaluation, we implement our model as a decentralized application and demonstrate its practical suitability in a preliminary user study

Tolerability of inhaled N-chlorotaurine in the pig model

<p>Abstract</p> <p>Background</p> <p>N-chlorotaurine, a long-lived oxidant produced by human leukocytes, can be applied in human medicine as an endogenous antiseptic. Its antimicrobial activity can be enhanced by ammonium chloride. This study was designed to evaluate the tolerability of inhaled N-chlorotaurine (NCT) in the pig model.</p> <p>Methods</p> <p>Anesthetized pigs inhaled test solutions of 1% (55 mM) NCT (n = 7), 5% NCT (n = 6), or 1% NCT plus 1% ammonium chloride (NH₄Cl) (n = 6), and 0.9% saline solution as a control (n = 7), respectively. Applications with 5 ml each were performed hourly within four hours. Lung function, haemodynamics, and pharmacokinetics were monitored. Bronchial lavage samples for captive bubble surfactometry and lung samples for histology and electron microscopy were removed.</p> <p>Results</p> <p>Arterial pressure of oxygen (PaO₂) decreased significantly over the observation period of 4 hours in all animals. Compared to saline, 1% NCT + 1% NH₄Cl led to significantly lower PaO₂values at the endpoint after 4 hours (62 ± 9.6 mmHg vs. 76 ± 9.2 mmHg, p = 0.014) with a corresponding increase in alveolo-arterial difference of oxygen partial pressure (AaDO₂) (p = 0.004). Interestingly, AaDO₂was lowest with 1% NCT, even lower than with saline (p = 0.016). The increase of pulmonary artery pressure (PAP) over the observation period was smallest with 1% NCT without difference to controls (p = 0.91), and higher with 5% NCT (p = 0.02), and NCT + NH₄Cl (p = 0.05).</p> <p>Histological and ultrastructural investigations revealed no differences between the test and control groups. The surfactant function remained intact. There was no systemic resorption of NCT detectable, and its local inactivation took place within 30 min. The concentration of NCT tolerated by A549 lung epithelial cells <it>in vitro </it>was similar to that known from other body cells (0.25–0.5 mM).</p> <p>Conclusion</p> <p>The endogenous antiseptic NCT was well tolerated at a concentration of 1% upon inhalation in the pig model. Addition of ammonium chloride in high concentration provokes a statistically significant impact on blood oxygenation.</p

Charakterisierung rekombinanter Peroxidasen hinsichtlich Effizienz und Umsetzung für ausgewählte Substrates

Abweichender Titel laut Übersetzung der Verfasserin/des VerfassersZsfassung in dt. SprachePeroxidases are oxidoreductases produced by a number of microorganisms and plants. They are heme proteins containing iron (III) protoporphyrin IX as the prosthetic group. Peroxidases have a molecular weight ranging from 30,000 to 150,000 Da and catalyze the reduction of peroxides, such as hydrogen peroxide but also oxidations of various organic and inorganic compounds. Peroxidase activity has been identified in plants, microorganisms and animals, where they play important roles. The potential of peroxidases is substantial and therefore they are the focus of interest of industries. Eucodis Bioscience is interested in an industrial use of heme-peroxidases and therefore produces various types of that enzyme. To understand the effect of different peroxidases specific enzyme-substrate reactions were studied in this thesis using an unsaturated fatty acid and its methyl ester as substrate. An analytical strategy was developed to analyze reaction samples by means of thin layer chromatography (TLC) and an efficient staining protocol but also with GC coupled to mass spectrometry (GCMS). This method combination allowed to determine the conversion rates of the enzymes and subsequently by studying the conversion rates the enzymatic reaction conditions were systematically optimized by qualitative and semi-quantitative evaluation of reaction products. In this thesis several reaction products could be identified by GCMS.7

A secure and auditable logging infrastructure based on a permissioned blockchain

Information systems in organizations are regularly subject to cyber attacks targeting confidential data or threatening the availability of the infrastructure. In case of a successful attack it is crucial to maintain integrity of the evidence for later use in court. Existing solutions to preserve integrity of log records remain cost-intensive or hard to implement in practice. In this work we present a new infrastructure for log integrity preservation which does not depend upon trusted third parties or specialized hardware. The system uses a blockchain to store non-repudiable proofs of existence for all generated log records. An open-source prototype of the resulting log auditing service is developed and deployed, followed by a security and performance evaluation. The infrastructure represents a novel software-based solution to the secure logging problem, which unlike existing approaches does not rely on specialized hardware, trusted third parties or modifications to the logging source. (C) 2019 Elsevier Ltd. All rights reserved

HyperSec: Visual Analytics for Blockchain Security Monitoring

Today, permissioned blockchains are being adopted by large organizations for business critical operations. Consequently, they are subject to attacks by malicious actors. Researchers have discovered and enumerated a number of attacks that could threaten availability, integrity and confidentiality of blockchain data. However, currently it remains difficult to detect these attacks. We argue that security experts need appropriate visualizations to assist them in detecting attacks on blockchain networks. To achieve this, we develop HyperSec, a visual analytics monitoring tool that provides relevant information at a glance to detect ongoing attacks on Hyperledger Fabric. For evaluation, we connect the HyperSec prototype to a Hyperledger Fabric test network. The results show that common attacks on Fabric can be detected by a security expert using HyperSec’s visualizations