  Blockchain technology has recently gained widespread attention by media,
businesses, public sector agencies, and various international organizations,
and it is being regarded as potentially even more disruptive than the Internet.
Despite significant interest, there is a dearth of academic literature that
describes key components of blockchains and discusses potential applications.
This paper aims to address this gap. This paper presents an overview of
blockchain technology, identifies the blockchain's key functional
characteristics, builds a formal definition, and offers a discussion and
classification of current and emerging blockchain applications.
