Let's start by introducing bitcoinjs-lib by working with private keys and public addresses. The module provides us with some useful components for working with elliptic curve keys.

To generate a new private key, we'll start Node.js from our command line and enter the following commands:

~ node
> var bitcoin = require('bitcoinjs-lib')
> var private_key = bitcoin.ECKey.makeRandom()
> console.log(private_key.toWIF())
KzgRK4nN6bcb5iQN8tLL85U5anc84uH7G9KtsZuqU23h5fN7Z6v4

From our example, you can see that we're importing the bitcoinjs library and calling ECKey.makeRandom(), which returns a random private key. We store an object that represents the key in a variable called private_key. On the third line, we print out the key in WIF format to the console. The result is a valid key from which we can compute a public address from:

> console.log(key.pub.getAddress().toString())
149TUxVkJzowbNDwExc34t4EfyNgAL1pco