About phoning home

Banks are - for their part - moving closer to the Trust Infrastructure ny taking own EUBWs in use and seeing to it that customers do the same - becoming capable sending and receiving veriifiable data to and from all directions.

Much to learn still. For example the "Phoning home" challenge and solution is not familiar to all of us.

It means that a wallet or credential contacts the original issuer or a central server every time you present or use it.
Meaning that your activity could be tracked - when, where, and to whom you shared a credential.

This breaks privacy and self-sovereignty. A verifiable credential should be self-contained: once issued, you can prove it’s authentic without giving the issuer a surveillance feed of your life or business.

Better approach: Use public key cryptography and trust registries so verifiers can check signatures offline or against a registry, not by pinging the issuer.

This is exactly what EUDI-wallet standards are aiming for—privacy-preserving proofs that are portable and don’t rat out the holder.