So, how many people are using Kerberos?
“Since MIT doesn’t sell Kerberos, and other organizations have produced their own software for it, so it’s really hard to say for sure how many people are using Kerberos. We know of one organization using the MIT Kerberos Software with over 50 million unique logons per month. But if you add up the users of all the various implementations, including Microsoft’s, a conservative estimate of how many are using Kerberos is, probably well over 100 million people, worldwide.