tendermint/docs/tendermint-core/light-client-protocol.md

# 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 [lite
package](https://godoc.org/github.com/tendermint/tendermint/lite).

## Overview

The objective of the light client protocol is to get a
commit for a recent 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](../spec/blockchain/encoding.md#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!