Why does presenting my credential to ten verifiers let them silently map my life?
Szansa
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.
Dlaczego to ważne
Unlinkable presentation is the primitive that makes selective disclosure mean privacy rather than just granularity, and the dominant deployed format cannot provide it.
Jak oceniam szansę
Wskaźnik Szansy to mój własny odczyt, a nie pomiar: jak bardzo boli, jak często daje się we znaki i jak niewiele istnieje dziś, by to rozwiązać. Wyższy wynik oznacza, że uważam problem za bardziej warty zbudowania.
Ile bólu sprawia, gdy się pojawia.
Jak często ludzie faktycznie na to trafiają.
Jak mało dobrych narzędzi istnieje dla tego dziś.
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