  Blockchain technology has gained tremendous popularity both in practice and
academia. The goal of this article is to develop a coherent overview of the
state of the art in blockchain technology, using a
systematic(i.e.,protocol-based, replicable), multivocal (i.e., featuring both
white and grey literature alike) literature review, to (1) define blockchain
technology (2) elaborate on its architecture options and (3) trade-offs, as
well as understanding (4) the current applications and challenges, as evident
from the state of the art. We derive a systematic definition of blockchain
technology, based on a formal concept analysis. Further on, we flesh out an
overview of blockchain technology elaborated by means of Grounded-Theory.
