Payment channels and the lightning network aren’t side chains. And there are no IOUs; not sure where that came from.<p>Good podcast about payment channels: <a href="https:&#x2F;&#x2F;letstalkbitcoin.com&#x2F;blog&#x2F;post&#x2F;lets-talk-bitcoin-219" rel="nofollow">https:&#x2F;&#x2F;letstalkbitcoin.com&#x2F;blog&#x2F;post&#x2F;lets-talk-bitcoin-219</a><p>And on the lightning network: <a href="https:&#x2F;&#x2F;letstalkbitcoin.com&#x2F;blog&#x2F;post&#x2F;lets-talk-bitcoin-242-meet-the-lightning-network" rel="nofollow">https:&#x2F;&#x2F;letstalkbitcoin.com&#x2F;blog&#x2F;post&#x2F;lets-talk-bitcoin-242-...</a><p>Lightning Network info site: <a href="http:&#x2F;&#x2F;lightning.network" rel="nofollow">http:&#x2F;&#x2F;lightning.network</a>