The Blockchain Muddle: A Bird's-Eye View on Blockchain Surveys

Since the emergence of Bitcoin, blockchains (BCs) have been applied not only in the finance sector, but also in various other domains like health care, education or Industry 4.0 resulting in numerous different BC platforms and substantial research work. This plenty of efforts yielded to several valuable scientific surveys classifying and evaluating existing BC platforms. Although each of them puts forward a somewhat consolidated view on the field, it is still challenging to get rid of the "blockchain muddle" preventing even a common perception of the core functionality of BCs. Instead of providing yet another BC overview we conduct a meta survey of existing BC studies and report on lessons learned in this paper, being the basis for our vision towards a UML-based reference model considering both, structural and behavioral aspects of BCs and thereby identifying the nucleus of BCs.