  Public blockchains should be able to scale with respect to the number of
nodes and to the transactions workload. The blockchain scalability trilemma has
been informally conjectured. This is related to scalability, security and
decentralization, stating that any improvement in one of these aspects should
negatively impact on at least one of the other twos. In fact, despite the large
research and experimental effort, all known approaches turn out to be
tradeoffs. We theoretically describe a new blockchain architecture that scales
to arbitrarily high workload provided that a corresponding proportional
increment of nodes is provisioned. We show that, under reasonable assumptions,
our approach does not require tradeoffs on security or decentralization. To the
best of our knowledge, this is the first result that disprove the trilemma
considering the scalability of all architectural elements of a blockchain and
not only the consensus protocol. While our result is currently only theoretic,
we believe that ot our approach may stimulate significant practical
contributions.
