We, the undersigned, believe that identity systems must be built without the technological ability for authorities to track when or where identity is used. Such tracking can occur when either the identity verifier or user’s application interacts with or “phones home” to the identity issuer or another third party. Identity systems that phone home facilitate centralized tracking and control, privacy invasions, and other potential abuses. If this capability exists within a digital identity system, even inactively, it will eventually be used.

We are concerned that many authorities are unnecessarily (and sometimes unknowingly) adopting identity systems with phone home capabilities. We call on authorities everywhere to favor identity solutions that have no phone home capability whatsoever, and to prioritize privacy and security over interoperability and ease of implementation.

Eliminating phone home capabilities is not the only requirement in building a privacy-protective identity system, but it is a vital one.