I\'m developing an app for my company and we\'re going through the process of slowly letting people into the \"beta\" by adding their iPads to the company\'s iOS Dev Center
Please use test flight to obtain UDID from testers but not using untrusted source e.g. http://get.udid.io/
You can 1. Invite testers in email from test flight webpage. Testers open the link in email and install a profile from test flight. Therefore developers can obtain UDIDs on the test flight webpage. 2. Add those UDIDs on the Apple provisioning portal.
(Ref: http://help.testflightapp.com/customer/portal/articles/829537-how-does-it-work-)
The process doesn't require testers to use Mac/ PC to obtain UDID (more convenient). And I think test flight is a company that can be trusted (no worries when passing UDID to this company).
I have tested this method and it works on iOS 8.