2 research outputs found
SoK: A Stratified Approach to Blockchain Decentralization
Decentralization has been touted as the principal security advantage which
propelled blockchain systems at the forefront of developments in the financial
technology space. Its exact semantics nevertheless remain highly contested and
ambiguous, with proponents and critics disagreeing widely on the level of
decentralization offered. To address this, we put forth a systematization of
the current landscape with respect to decentralization and we derive a
methodology that can help direct future research towards defining and measuring
decentralization. Our approach dissects blockchain systems into multiple
layers, or strata, each possibly encapsulating multiple categories, and enables
a unified method for measuring decentralization in each one. Our layers are (1)
hardware, (2) software, (3) network, (4) consensus, (5) economics
("tokenomics"), (6) API, (7) governance, and (8) geography. Armed with this
stratification, we examine for each layer which pertinent properties of
distributed ledgers (safety, liveness, privacy, stability) can be at risk due
to centralization and in what way. Our work highlights the challenges in
measuring and achieving decentralization, points to the degree of
(de)centralization of various existing systems, where such assessment can be
made from presently available public information, and suggests potential
metrics and directions where future research is needed. We also introduce the
"Minimum Decentralization Test", as a way to assess the decentralization state
of a blockchain system and, as an exemplary case, we showcase how it can be
applied to Bitcoin