Trillian is an implementation of the concepts described in the
Verifiable Data Structures white paper, which in turn is an extension
and generalisation of the ideas which underpin Certificate Transparency.

Trillian implements a Merkle tree whose contents are served from a data
storage layer, to allow scalability to extremely large trees. On top of
this Merkle tree, Trillian provides the following:

- An append-only Log mode, analogous to the original Certificate
  Transparency logs. In this mode, the Merkle tree is effectively filled
  up from the left, giving a dense Merkle tree.

Note that Trillian requires particular applications to provide their own
personalities on top of the core transparent data store functionality.