Blockchain

Why does presenting my credential to ten verifiers let them silently map my life?

Oportunidad

Every SD-JWT credential, the dominant format being deployed in EUDI Wallets across EU member states in 2026, carries a single issuer signature that is identical across all presentations. Any two verifiers who receive the same credential can share that token and link both visits to the same person. BBS+ with randomizable signatures prevents this correlation, but it is computationally heavier and production wallet support is thin. An IEEE EuroS&P 2026 paper confirms that issuer-verifier unlinkability is structurally impossible in salted-hash selective disclosure schemes like SD-JWT without issuing fresh credential batches per presentation, an operational burden no major deployment has solved. The hundreds of millions of wallets rolling out under eIDAS 2.0 today will silently correlate holders across every verifier they interact with for the lifetime of the credential.

Por qué importa

Unlinkable presentation is the primitive that makes selective disclosure mean privacy rather than just granularity, and the dominant deployed format cannot provide it.

Cómo evalúo la oportunidad

La Puntuación de Oportunidad es mi propia lectura, no una medición: cuánto duele, con qué frecuencia aparece y qué tan poco existe para resolverlo hoy. Un valor más alto significa que creo que vale más la pena construirlo.

Gravedad8/10

Cuánto dolor causa cuando aparece.

Frecuencia9/10

Con qué frecuencia la gente se topa con ello.

Espacio en blanco8/10

Qué tan pocas herramientas buenas existen para ello hoy.