PKI-based authentication of blockchain addresses

A method, comprising:

• receiving, at a server computer system from a registering entity, a registration request for a blockchain address, wherein the blockchain address corresponds to a first public key of a blockchain key pair of the registering entity;
• verifying, by the server computer system, the registration request;
• and
• in response to the registration request being verified, storing, by the server computer system, registration information from the registration request in a first record of a registry of a blockchain, wherein the registration information includes a signed message that includes the blockchain address of registering entity;
• and
• wherein the registration information is retrievable from the registry and is usable to:
• verify a certificate of the registering entity using a certificate authority (CA) public key, the certificate being signed by a CA private key;
• and
• verify the signed message using a second public key of a public key infrastructure (PKI) key pair of the registering entity, the signed message being signed by a private key of the PKI pair and corresponding to the second public key included in the certificate to establish an association between the blockchain address and the registering entity, wherein the second public key of the PKI pair is distinct from the first public key of the blockchain key pair;
• and
• determine identity information of the registering entity.

A method, comprising:

• detecting, by an application executing on a computer system, a request for a first user to perform a blockchain transaction, the request including information specifying a blockchain address of a second user on a blockchain, wherein the blockchain address corresponds to a first public key of a blockchain key pair of the second user;
• invoking, by the application, an application programming interface (API) of a registry of the blockchain, wherein the invoking includes passing the blockchain address as a parameter of the API;
• identifying, by the application in response to information returned from the registry, registered information stored in a record of the registry that corresponds to the blockchain address, wherein the registered information includes a signed message that includes the blockchain address of the second user;
• verifying, by the application, the registered information, wherein the verifying includes:
• verifying a certificate of the second user using a certificate authority (CA) public key, the certificate including a second public key of a public key infrastructure (PKI) key pair of the second user, wherein the second public key of the PKI pair is distinct from the first public key of the blockchain key pair;
• and
• verifying a signed message using the public key of the second user, the signed message being signed by a private key of the PKI pair and corresponding to the second public key included in the certificate to establish an association between the blockchain address and the second user;
• and
• in response to the registered information being verified, providing, by the application, identity information of the second user to the first user.