Blockchain based verifiability of user status

A method, comprising:

• extracting a data object from a machine-readable code, where the data object comprises a first field of data that is signed with a digital signature of a private key and a second field of data that is hashed before being signed with the digital signature so that a value of the second field is not disclosed when the second field is verified;
• retrieving an identifier of an issuer of the data object from the data object;
• retrieving a public key from a blockchain based on the identifier of the issuer;
• verifying the digital signature of the private key based on the public key;
• verifying that a schema identifier of the first field matches a schema identifier of a first stored schema on the blockchain;
• verifying that a hash of a schema identifier of the second field matches a hash of a second schema identifier of a second stored schema on the blockchain;
• and
• verifying that the data object is trustworthy based on both the verification of the digital signature and the verification of the schema identifiers.

A computer program product comprising a non-transitory computer-readable medium storing instructions that, when executed by a processor, cause the processor to perform:

• extracting a data object from a machine-readable code, where the data object comprises a first field of data that is signed with a digital signature of a private key and a second field of data that is hashed before being signed with the digital signature so that a value of the second field is not disclosed when the second field is verified;
• retrieving an identifier of an issuer of the data object from the data object;
• retrieving a public key from a blockchain based on the identifier of the issuer;
• verifying the digital signature of the private key based on the public key;
• verifying that a schema identifier of the first field matches a schema identifier of a first stored schema on the blockchain;
• verifying that a hash of a schema identifier of the second field matches a hash of a second schema identifier of a second stored schema on the blockchain;
• and
• verifying that the data object is trustworthy based on both the verification of the digital signature and the verification of the schema identifiers.