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oauth-wg / oauth-selective-disclosure-jwt

https://datatracker.ietf.org/doc/draft-ietf-oauth-selective-disclosure-jwt/
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The definition of "key binding" would need to be reworded #492

Closed Denisthemalice closed 2 weeks ago

Denisthemalice commented 3 weeks ago

The current definition of key Binding is:

Key Binding: Ability of the Holder to prove legitimate possession of an SD-JWT by proving control over a private key during the presentation. When utilizing Key Binding, an SD-JWT contains the public key corresponding to the private key controlled by the Holder (or a reference to this public key).

Talking of a "legitimate possession" is an abuse of language. Who possesses the private key is unknown. Even when the key is controlled by a Holder, the End-User can decide to perform cryptographic computations with the private key for the benefit of one or more End-Users. If the set of claims does not allow to uniquely identify the End-User, the End-User cannot be caught. In that case, the End-User can even monetize his services for the benefit of hundred of users.

Replace this definition by:

Key Binding: Ability to demonstrate to a Verifier that a cryptographic result computed over a data structure using a private key corresponding to a public key contained in a SD-JWT is correct.