Not to nit-pick, but a 'random number' is not guaranteed to be different the next time it's requested. There is a possibility two people will hit it within a second of each other (thus getting the same time) and get the same random number, thus giving them the same unique ID. Granted, the probability is low, but if you get a lot of ID requests, this will be a very real concern. I usually combine the process ID of the process making the request in with that, since it's highly unlikely you will iterate through the system's available process pool within 1 second of time, and combined with a random number like you're doing, makes it for all practical purposes completely unique.