# Bitcoin: A Peer-to-Peer Electronic Cash System

## Intriduction

## Transaction

## Timestamp server

A timestamp servre work by

## proof of work

In bitcoin system, the most interesting part for me is the way bitcoin giving reward by calculating hash. Every block need a random number (nonce). The system may not confirm the block until the hash result met the require, and this difficulty of this process will increase with the mount of confirmed blocks.

Also, this process are irreversible. If attacker want to modify the past block, they need to redo all the block after the block which they start to modify. This mechanism make attacker more difficult to redirect hole chain to wrong way.

## Network

## Incentive