Patent ID: 9635012
Date: 2017-04-25
CPC Classifications: H04L,H04W

Claim:
1. A method for deriving a verification token from a credential, the credential being a set of attributes certified by an issuer to a user using a public key of the issuer, the method comprising: generating the verification token out of the credential, wherein the verification token comprises at least one commitment, wherein a commitment is a blinded version of an attribute; generating an opening key for the verification token enabling a generation of a confirmation for a validity of the attribute, wherein the generating the verification token comprises binding of the verification token to a context string for preventing the verification token to be reusable together with a different context string; performing the generation of the verification token and the opening key in a first system; transferring a first tuple comprising an attribute, the verification token, and the opening key from the first system, the first tuple receivable by a second system, such that at the second system a confirmation about the validity of the attribute based on the first tuple and the public key of the issuer is obtainable; transferring from the first system a second tuple comprising a plurality of attributes together with a corresponding verification token comprising commitments for the plurality of attributes, and corresponding opening keys for each attribute and commitment combination, the second tuple being receivable by the second system; transferring from the second system to a third system, a subset of the plurality of attributes, the verification token, and a subset of opening keys related to the subset of the plurality of attributes; and obtaining at the third system a confirmation about the validity of the subset of the plurality of attributes based on the verification token, the subset of opening keys, and the public key of the issuer, wherein the obtaining of a confirmation at the third system is performed with a respective certified function from the issuer.