tendermint/docs/light-client-protocol.rst

Light Client Protocol
=====================

Light clients are an important part of the complete blockchain system
for most applications. Tendermint provides unique speed and security
properties for light client applications.

See our developing `light-client
repository <https://github.com/tendermint/light-client>`__.

Overview
--------

The objective of the light client protocol is to get a
`commit <./validators.html#committing-a-block>`__ for a recent
`block hash <./block-structure.html#block-hash>`__ where the commit
includes a majority of signatures from the last known validator set.
From there, all the application state is verifiable with `merkle
proofs <./merkle-trees#iavl-tree>`__.

Properties
----------

-  You get the full collateralized security benefits of Tendermint; No
   need to wait for confirmations.
-  You get the full speed benefits of Tendermint; transactions commit
   instantly.
-  You can get the most recent version of the application state
   non-interactively (without committing anything to the blockchain).
   For example, this means that you can get the most recent value of a
   name from the name-registry without worrying about fork censorship
   attacks, without posting a commit and waiting for confirmations. It's
   fast, secure, and free!