Exploring Potentials and Challenges of Blockchain-based Public Key Infrastructures

Traditional public key infrastructures (PKIs), in particular, X.509 and PGP, is plagued by security and usability issues. As reoccurring incidents show, these are not only of theoretical nature but allow attackers to inflict severe damage. Emerging blockchain technology allows for advances in this area, facilitating a trustless immutable ledger with fast consensus. There have been numerous proposals for utilization of the blockchain in the area of PKI, either as extensions upon existing methods or independent solutions. In this paper, we first study traditional PKI, then proceed with novel approaches, showing how they can improve upon recent issues. We provide a comprehensive evaluation, finding that independent blockchain-based solutions are preferable in the future, mainly due to their stronger security. However, global adoption of these yet requires advances in blockchain development, e.g., concerning scalability.

Overview of licensing platforms based on distributed ledger technology

The licensing of creative work is of broad and current interest. The European Commission proposes that when uploading a licensed digital work, the uploader should be checked by the system that one has the necessary rights. Technically this law is difficult to implement, as images with different intentions are shared, and even small changes like watermarks make it difficult to reveal similarities. The characteristics of distributed ledger technology could provide excellent support for the licensing and management of the rights of use. In this work, non-technical and technical criteria are defined to achieve an overview of the state-of-the-art solutions in the field of blockchain-based licensing platforms. Based on the criteria, different licensing platforms are reviewed, and the results are presented in a comparison matrix.

OriginStamp: A blockchain-backed system for decentralized trusted timestamping

Currently, timestamps are certified by central timestamping authorities, which have disadvantages of centralization. The concept of the decentralized trusted timestamping (DTT) was developed by Gipp et al. to address these drawbacks. The paper provides insights into the architecture and implementation of a decentralized timestamp service taking the integration of multiple blockchain types into account. Furthermore, the components are introduced and the versatile application scenarios are presented. A future direction of research is the evaluation of blockchain technology and their suitability for timestamping.

  • Authors: Thomas Hepp, Alexander Schoenhals, Christopher Gondek, Bela Gipp
  • Published: December 2018
  • Publisher: De Gruyter Oldenbourg
  • DOI: 10.1515/itit-2018-0020
  • Bibtex: Download
  • Preprint: Download

On-chain vs. off-chain storage for supply-and blockchain integration

Supply chains are the basis of most everyday life products. Both data integrity and authenticity of related information have severe implications for quality and safety of end-products. Hence, tamper-proof storage is necessary that prevents unauthorized modifications. We examine peer-reviewed blockchain technologies according to four criteria relevant to supply chains: On-chain storage, off-chain storage, verification cost and secure data sharing. Our evaluation yields an overview of concepts for modeling supply chain processes and points out that on-chain storage is currently not practical.

  • Authors: Thomas Hepp, Matthew Sharinghousen, Philip Ehret, Alexander Schoenhals, Bela Gipp
  • Published: December 2018
  • Publisher: De Gruyter Oldenbourg
  • DOI: 10.1515/itit-2018-0019
  • Bibtex: Download
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Design Thinking using the Blockchain: Enable Traceability of Intellectual Property in Problem-Solving Processes for Open Innovation

In this vision paper, we present an approach that makes it possible to protect developed ideas and early concepts even during their systematical development. We take the Design Thinking process as an example, in which interfaces are used for individual stages (understand, observe, define, ideate, prototype, test) to digitally record verbal, written or sketched, and even modeled or constructed outcome. This outcome is recorded and linked to the originating person. To guarantee both proof-of-existence and proof-of-origin, a unique hash is generated from each digital artifact stored and embedded into the Bitcoin Blockchain by the OriginStamp decentralized trusted timestamping service. Once this unique fingerprint is embedded in a transaction in the underlying Blockchain network, it can be proven where particular contributions originated due to the characteristics of Blockchain architecture. By setting up a decentralized tamper-proof means of record keeping, the entire innovation chain from the first ideation to the beginning of production is verifiably stored. By providing a clear proof-of-origin, all innovators (even competitors) could continue to work on existing problem-solving process and add their contribution proportionately, depending on the state of innovation development. This concept enables an Open Innovation ecosystem, which has the potential to increase the innovation potential of companies immensely. Additionally, inventions that are not patentable because they do not comply with the strict regulations of patent law can still be published and protected because the information about the origin of the respective contribution is guaranteed.

Securing physical assets on the blockchain: Linking a novel object identification concept with distributed ledgers

The use of blockchain technology to track physical assets is not new. However, the state of the art concepts are not applicable due to several limitations. One limitation is the scalability of blockchains with regard to the number of transactions that can be processed by the network. The well-established technology in tracking products is based on RFID chips that can be cloned. This paper provides insights into how objects can be protected and monitored by a varnish with a unique crack pattern, as an example of a Physical Unclonable Function. The perceptual hash of the unique pattern is used to encrypt the associated data to ensure privacy. Instead of logging each event on the blockchain individually, which is not possible due to the limited transaction throughput, OriginStamp is used to preserve data integrity on the blockchain. OriginStamp aggregates events, combines them through hashing and embeds this hash into a Bitcoin transaction. Once the Bitcoin network mines the transaction into a block and confirms it, the timestamp is considered as immutable proof of existence. With this approach, the integrity of tracking data cannot be contested. In the future, the craquelure-based tracking approach could be extended to supply chain integration to secure the origin of products, including prevention of counterfeiting, securing the place of manufacture for trademark law or state surveillance of the agricultural economy.

  • Authors: Thomas Hepp, Patrick Wortner, Alexander Schönhals, Bela Gipp
  • Published: June 2018
  • Publisher: Association for Computing Machinery
  • DOI: 10.1145/3211933.3211944
  • Bibtex: Download
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Giveme5W: main event retrieval from news articles by extraction of the five journalistic w questions

Extraction of event descriptors from news articles is a commonly required task for various tasks, such as clustering related articles, summarization, and news aggregation. Due to the lack of generally usable and publicly available methods optimized for news, many researchers must redundantly implement such methods for their project. Answers to the five journalistic W questions (5Ws) describe the main event of a news article, i.e., who did what, when, where, and why. The main contribution of this paper is Giveme5W, the first open-source, syntax-based 5W extraction system for news articles. The system retrieves an article’s main event by extracting phrases that answer the journalistic 5Ws. In an evaluation with three assessors and 60 articles, we find that the extraction precision of 5W phrases is p=0.7 .

VMEXT: a visualization tool for mathematical expression trees

Mathematical expressions can be represented as a tree consisting of terminal symbols, such as identifiers or numbers (leaf nodes), and functions or operators (non-leaf nodes). Expression trees are an important mechanism for storing and processing mathematical expressions as well as the most frequently used visualization of the structure of mathematical expressions. Typically, researchers and practitioners manually visualize expression trees using general-purpose tools. This approach is laborious, redundant, and error-prone. Manual visualizations represents a user’s notion of what the markup of an expression should be, but not necessarily what the actual markup is. This paper presents VMEXT – a free and open source tool to directly visualize expression trees from parallel MathML. VMEXT simultaneously visualizes the presentation elements and the semantic structure of mathematical expressions to enable users to quickly spot deficiencies in the Content MathML markup that does not affect the presentation of the expression. Identifying such discrepancies previously required reading the verbose and complex MathML markup. VMEXT also allows one to visualize similar and identical elements of two expressions. Visualizing expression similarity can support support developers in designing retrieval approaches and enable improved interaction concepts for users of mathematical information retrieval systems. We demonstrate VMEXT’s visualizations in two web-based applications. The first application presents the visualizations alone. The second application shows a possible integration of the visualizations in systems for mathematical knowledge management and mathematical information retrieval. The application converts LATEX input to parallel MathML, computes basic similarity measures for mathematical expressions, and visualizes the results using VMEXT.

Applying visual analytics to explore and analyze movement data

The VAST Challenge 2015 movement dataset is mirroring current challenges in the analysis of large spatiotemporal datasets. We present a tool featuring different exploratory approaches analyze and visualize spatiotemporal data to build and confirm hypotheses. Our tool helps the user to find patterns, anomalies and groups in a data set that can not be processed manually. We present custom visualizations to solve the tasks stated by the VAST 2015 Mini-Challenge (MC1).

  • Authors: Eren Cakmak, Alexander Gärtner, Thomas Hepp, Juri Buchmüller, Fabian Fischer, Daniel A Keim
  • Published: October 2015
  • Publisher: IEEE
  • DOI: 10.1109/VAST.2015.7347643
  • Bibtex: Download
  • Preprint: Download