  As we observe a trend towards the recentralisation of the Internet, this
paper raises the question of guaranteeing an everlasting decentralisation. We
introduce the properties of strong and soft uncentralisability in order to
describe systems in which all authorities can be untrusted at any time without
affecting the system. We link the soft uncentralisability to another property
called perfect forkability. Using that knowledge, we introduce a new
cryptographic primitive called uncentralisable ledger and study its properties.
We use those properties to analyse what an uncentralisable ledger may offer to
classic electronic voting systems and how it opens up the realm of
possibilities for completely new voting mechanisms. We review a list of
selected projects that implement voting systems using blockchain technol- ogy.
We then conclude that the true revolutionary feature enabled by uncentralisable
ledgers is a self-sovereign and distributed identity provider.
