Method for responding to published content, method for assessing a response to published content, computer programs, non-transitory machine-readable media, and apparatuses therefor

1 . A method for responding to published content associated with a second digital identity, the method comprising:

generating, based on (i) one or more unique verifiable credential of a first digital identity associated with a response to the published content associated with the second digital identity and (ii) information related to the second digital identity associated with the published content, a cryptographic proof for proving that the first digital identity is holder of the one or more unique verifiable credential, wherein the cryptographic proof is indicative of (a) the second digital identity associated with the published content and (b) a hash value of the one or more unique verifiable credential of the first digital identity associated with the response; and

outputting data indicative of the response associated with the first digital identity to the published content associated with the second digital identity together with (i) the cryptographic proof that is indicative of (a) the second digital identity associated with the published content and (b) a hash value of the one or more unique verifiable credential of the first digital identity associated with the response and (ii) the hash value of the one or more unique verifiable credential of the first digital identity associated with the response.

2 . The method of claim 1 ,

wherein generating the cryptographic proof comprises generating another hash value by hashing a combination of the hash value and the information related to the second digital identity, and

wherein the cryptographic proof is indicative of the other hash value.

3 . The method of claim 1 ,

wherein the second digital identity is a self-sovereign identity relating to a public decentralized identifier, DID, and

wherein the information related to the second digital identity includes the public DID.

4 . The method of claim 1 , wherein the response comprises at least one of a vote, a rating, and a comment of the first digital identity on the published content.

5 . The method of claim 1 , wherein the one or more unique verifiable credential comprises at least one of a unique identification number and unique biometric information representative of a human user represented by the first digital identity.

6 . The method of claim 1 , wherein the cryptographic proof is a zero-knowledge proof.

7 . The method of claim 1 , wherein

the one or more unique verifiable credential includes a digital equivalent of an identification document issued by a governmental authority to a natural person, and

the natural person defines an entity associated with the first digital identity.

8 . The method of claim 1 , wherein

the cryptographic proof includes a zero-knowledge proof generated using a predetermined deterministic function that takes as input a combination of (i) the hash value of the one or more unique verifiable credential of the first digital identity associated with the response and (ii) a public decentralized identifier of the second digital identity associated with the published content, and

the cryptographic proof indicates a resulting hash value of the combination without revealing a plaintext of the one or more unique verifiable credential of the first digital identity associated with the response.

9 . A method for assessing a response associated with a first digital identity to published content associated with a second digital identity, the method comprising:

receiving data indicative of the response associated with the first digital identity to the published content associated with the second digital identity;

receiving a hash value of one or more unique verifiable credential of the first digital identity associated with the response;

receiving a cryptographic proof for proving that the first digital identity associated with the response is holder of the one or more unique verifiable credential, wherein the cryptographic proof is indicative of (a) the second digital identity associated with the published content and (b) the hash value of the one or more unique verifiable credential of the first digital identity associated with the response; and

assessing the data indicative of the response associated with the first digital identity based on (i) the cryptographic proof that is indicative of (a) the second digital identity associated with the published content and (b) the hash value of the one or more unique verifiable credential of the first digital identity associated with the response and (ii) the hash value of the one or more unique verifiable credential of the first digital identity associated with the response.

10 . The method of claim 9 , wherein assessing the data comprises comparing the hash value with the cryptographic proof.

11 . The method of claim 9 , wherein the method further comprises processing the data based on assessing the data.

12 . The method of claim 9 ,

wherein the cryptographic proof is indicative of a first other hash value obtained by hashing a combination of the hash value and information related to the second digital identity, and

wherein assessing the data comprises:

obtaining a second other hash value by hashing the hash value and the information related to the second digital identity; and

comparing the first and the second other hash value.

13 . The method of claim 9 , wherein the second digital identity is a self-sovereign identity relating to a public decentralized identifier, DID.

14 . The method of claim 9 , wherein the method further comprises forwarding the hash value and the cryptographic proof to circuitry of a third-party verification service and requesting verification that the first digital identity is holder of the one or more unique verifiable credential.

15 . The method of claim 9 , wherein the method comprises:

storing the hash value;

receiving other data together with a further hash value obtained from one or more unique verifiable credential of a third digital identity; and

assessing the other data based on a comparison of the stored hash value and the further hash value.

16 . The method of claim 9 , wherein the cryptographic proof is a zero-knowledge proof.

17 . A non-transitory machine-readable medium having stored thereon a program having a program code for performing the method of claim 1 , when the program is executed on a processor or a programmable hardware.

18 . An apparatus for responding to published content associated with a second digital identity, the apparatus comprising:

one or more interface for communicating; and

processing circuitry configured to:

generate, based on (i) one or more unique verifiable credential of a first digital identity associated with a response to the published content associated with the second digital identity and (ii) information related to the second digital identity associated with the published content, a cryptographic proof for proving that the first digital identity is holder of the one or more unique verifiable credential, wherein the cryptographic proof is indicative of (a) the second digital identity associated with the published content and (b) a hash value of the one or more unique verifiable credential of the first digital identity associated with the response; and

output, using the one or more interface, data indicative of the response associated with the first digital identity to the published content associated with the second digital identity together with (i) the cryptographic proof that is indicative of (a) the second digital identity associated with the published content and (b) a hash value of the one or more unique verifiable credential of the first digital identity associated with the response and (ii) the hash value of the one or more unique verifiable credential of the first digital identity associated with the response.

19 . An apparatus for assessing a response associated with a first digital identity to published content associated with a second digital identity, the apparatus comprising:

one or more interface for communicating; and

processing circuitry configured to:

receive, using the one or more interface, data indicative of the response associated with the first digital identity to the published content associated with the second digital identity;

receive, using the one or more interface, a hash value of one or more unique verifiable credential of the first digital identity associated with the response;

receive, using the one or more interface, a cryptographic proof for proving that the first digital identity associated with the response is holder of the one or more unique verifiable credential, wherein the cryptographic proof is indicative of (a) the second digital identity associated with the published content and (b) the hash value of the one or more unique verifiable credential of the first digital identity associated with the response; and

assess the data indicative of the response associated with the first digital identity based on (i) the cryptographic proof that is indicative of (a) the second digital identity associated with the published content and (b) the hash value of the one or more unique verifiable credential of the first digital identity associated with the response and (ii) the hash value of the one or more unique verifiable credential of the first digital identity associated with the response.