How to get name of logged in user from cookie

Hi

I authenticated with persona using the _persona endpoint. I was able to retrieve the cookie sent back on the call. It had a named entry syncGatewaySession and an alpha numerical value. Can I get the name of the logged in user from that cookie.

Could I access that cookie after the user exits the app then starts using it again within the day. If I get the user name from there I don’t have to force the user to login again through persona until the cookie expires. Does that seem correct?

Thanks.