Blockchain & Self-Sovereign Identity

Finding consensus is the major challenge of a decentralised, non-hierarchical network that consists of unknown and therefore untrusted nodes. Blockchain technology could be a solution to this problem, often referred to as Byzantine Generals problem.

The first Use-Case of Blockchain technology was the Bitcoin payment system. The technology has steadily gained traction, with 2017 being the breakout year for public awareness on the topic.

Application of Blockchain technology is not limited to cryptocurrency payment systems however. The immutability of the Blockchain is utilised by projects that require transparent auditing such as governmental data archiving. Another major development in the Blockchain space is the concept of smart contracts, programs that are written on the Blockchain and executed in a decentralised way. Using such decentral code execution even more application fields might be tackled with the use of Blockchain technology.

Identity Management is one of the most promising applications for Blockchain technology.

Research Topics and Projects

Self-Sovereign Identity Systems

Blockchain technology eliminates the need for a trusted third party and therefore, has significant applicability in the domain of identity management. 

In traditional identity management digital identities and their attributes are issued by an identity provider that acts as a trusted third party. The Blockchain technology enables a self-sovereign identity, which can exist independently from service providers (see Figure below). This contrasts to the current ecosystem, which is dominated by few large identity providers such as Facebook or Google.

Several interesting research questions arise due to the transition from centrally managed to distributed trust.

[Translate to Englisch:] Bilder: gestaltet von Freepik, geändert und angepasst von HPI

We research the application of Blockchain-based identity management in general and specifically the creation of an identity provider. Accompanied by this research we analyse trust flows in the distributed environment and investigate the coupling to conventional identity management systems.


Blockchain Systems

Security - As Self-Sovereign Identity systems utilise Blockchain technology as an essential part of their architecture, we also investigate security properties of Blockchain networks. This is comprised of multiple layers. The peer-to-peer network, the exchange of transactions and blocks over that network and the consensus protocol are the core of the analysis. Systems that are built on top of that construct are vulnerable too.


Scalability - One of the main issues in Blockchain systems currently is their limited scalability. On-Chain scaling through sharding or more efficient consensus protocols are proposed solutions. Additionally second layer protocols (off-chain scaling) are possible scaling solutions. Other directions have been explored, i.e. restructuring Blockchains from chains to directed acyclic graphs (DAGs).


  • Meinel, Gayvoronskaya, and Schnjakin:  “Blockchain: Hype oder Innovation“, 2018
  • Grüner, Mühle, Gayvoronskaya and Meinel: “A Quantifiable Trust Model for Blockchain-based Identity Management”, IEEE International Conference on Blockchain, 2018 (accepted)


  • Prof. Dr. Christoph Meinel (Supervisor)

  • Tatiana Gayvoronskaya (PhD Student, H-1.12)

  • Alexander Mühle (PhD Student, H-1.12)

  • Andreas Grüner (External PhD Student)