We expect it to take about 3-5 seconds to sync right now. As the blockchain becomes larger it will take MUCH longer to sync. If it’s taking longer right now, you might have a blocked networking port or something? We can help troubleshoot if you post logs.
This gets at the heart of one of the core problems of privacy preserving cryptocurrency systems: how does a user get their balance quickly? One way is to run a full node and check every transaction in the ledger against your view key. That works fine for an individual, but it won’t work for a service provider. Even if you gave your view key to a service provider to check, the service provider would have to check every view key in their database against every incoming transaction (in Big O notation we would describe this as order N^2, which is bad).
The punchline is that every single privacy protecting cryptocurrency has this problem… Until now. We have a solution that we call Fog that reduces it to roughly 1 operation per transaction (O(N)) instead of 1 operation per user per transaction (O(N^2)). We call this Fog , as in a cloud you can’t see through. We haven’t unveiled the design for this, but once we do, you’ll be able to connect to Fog and have just a thin client on your desktop or phone instead of having to download the ledger AND you’ll be able to do that with a reasonable security model for Fog.
Fog isn’t announced yet and we haven’t dropped docs for it, but it’s coming ;).