# Phone Validator

Classics blockchain such as Ethereum can support both full nodes and light clients, it contains a peer to peer layer which allows nodes to send messages to each other.&#x20;

A light client is a cheaper alternative to a full node (from a bandwidth and resource consumption perspective) since it only downloads the header from each block and trusts the full nodes to check that the state transitions are correct (in other words, a light client trusts the full nodes it is peered with to verify that the block producer hasn't tried to print new coins, spend coins from an address for which they don’t have the private key, or make larger blocks than the consensus rules allow them to do).

Vitalik Buterin's Endgame: block production is centralized, block verification is de-trusted and highly decentralized, and remains censorship-proof.

WebKey mobile phones, as the light nodes, are perfectly capable of contributing just a small amount of data to the network to make the whole network of great significance!&#x20;

To achieve this, it requires the phone to pay only a minimal amount of network bandwidth, CPU, RAM and battery resources to join in. Clearly, smartphones in the 5G times will have no trouble making this happen!
