This is a security and simplicity proposition. There will be persistent data via archive nodes in due course. I continually strive to ensure we reduce account info and ensure all people get a chance to farm on even the smallest devices. This also means you do not have a persistent vault ID and it’s re calculated at every reboot. It has very interesting implications and will move data much faster across the network. To be persistent we had to store the vault private key locally (there are some options). This way there is nothing/nada to steal from your computer that is going to help any attacker. So it is pretty nice in many ways.
In essence it allows much smaller fast/off/on nodes to take part in the network easily. As a vault stays on longer it holds data for a while and grows rank (automatically) per session. It makes rank calculation very simple and also makes ‘gaming’ the system significantly harder (it was already very hard).
Archive nodes though will be required anyway to take care of very large aggregate chunks and these will look very similar to the older vaults, but much harder to become one.
I will do a write up about this and another few small changes that have some staggering implications for security very soon. As soon as we get testnet3 up and feature complete.