As the ArcGIS software and license administrator for a large group of users one of my responsibilities is protect the use of our Single Use authorization codes. One way I think these codes can be protected is to not allow the users of the provisioning files to be able to see the codes when the file is used during the authorization process. Here are a few suggestions. 1) When the authorization pages showing the codes appear don't show the codes but just say that a code is being used for the selected product. 2) Just skip those pages in the authorization process and go straight to the end and show the list of products that will be authorized and give the user the option to change. 3) Along with the other suggestions also encrypt the provisioning file itself so that the user cannot open the file in a text editor to see the codes. As the system is setup now once the provisioning file is given to a user I have lost any ability to protect the codes from being given to others and used to authorize licenses not using a provisioning file.
