iOS将核心数据保存到服务器/云

I'm using core data in our iOS universal application and want the ability for the user to back their data up to our server. So they can log in with another device and pull down that data to that device. Has anyone got any advice on this? I want to analyse the data at the server to synchronise information with our stores as well, so the data must be readable via the server end as well.I'm using core data in our iOS universal applic