On 09/10/2017 08:10, Padma Pillay-Esnault wrote: ... > Using the cell phone example to tie an end device to a human. Today, > doesn't SIM cards tie at some level you as a subscriber to your device and > do the accounting? The SIM database is not publicly accessible are they? It's available to repressive governments. Also, I don't know if there have been wholesale thefts or leaks of parts of the SIM database, but there have certainly been breaches of the secrecy by corrupt law enforcement agents or telco employees. So the IETF has to be careful not to create another similar exposure. Brian