Method for certificate generation and revocation with privacy preservation

A method for certificate generation with privacy preservation, adapted to a communication within a certificate authority (CA), the method comprising:

• determining a secret value to be used by a certificate authority and an entity;
• constructing a key tree based on the secret value, wherein the leaves of the key tree represent derived keys for the certificates for the entity;
• and
• generating two or more certificates for the entity based in part on the key tree leaves, each of the two or more certificates for the entity being associated with a different leaf of the key tree leaves;
• and
• causing the two or more certificates to be provided to the entity.

A non-transitory computer-readable storage medium comprising computer program instructions stored therein, the computer program instructions, when executed on a computer, configured to:

• determine that one or more certificates for an entity should be revoked;
• determine a minimum key node set of a key tree that covers the one or more certificates to be revoked;
• add the minimum key node set to a certificate revocation list by at least adding at least a node index and a derived secret key corresponding to the node index to the certificate revocation list, the derived secret key being different from any of the one or more certificates and the node index defining at least one function to apply to the derived secret key to identify the one or more certificates to be revoked;
• and
• provide the certificate revocation list to one or more entities.

A non-transitory computer-readable storage medium comprising computer program instructions stored therein, the computer program instructions, when executed on a computer, configured to:

• determine a secret value to be used by a certificate authority and an entity;
• construct a key tree based on the secret value, wherein the leaves of the key tree represent derived keys for the certificates for the entity;
• and
• generate two or more certificates for the entity based in part on the key tree leaves, each of the two or more certificates for the entity being associated with a different leaf of the key tree leaves;
• and
• cause the two or more certificates to be provided to the entity.

An apparatus comprising:

• at least one processor,
• and at least one memory including computer program instructions, the memory and computer program instructions being configured to, in cooperation with the processor, cause the apparatus to:
• determine that one or more certificates for an entity should be revoked;
• determine a minimum key node set of a key tree that covers the one or more certificates to be revoked;
• add the minimum key node set to a certificate revocation list by adding at least a node index and a derived secret key corresponding to the node index to the certificate revocation list, the derived secret key being different from any of the one or more certificates and the node index defining at least one function to apply to the derived secret key to identify the one or more certificates to be revoked;
• and
• cause sending of the certificate revocation list to one or more entities.

An apparatus comprising:

• at least one processor,
• and at least one memory including computer program instructions, the memory and computer program instructions being configured to, in cooperation with the processor, cause the apparatus to:
• determine a secret value to be used by a certificate authority and an entity;
• construct a key tree based on the secret value, wherein the leaves of the key tree represent derived keys for the certificates for the entity;
• and
• generate two or more certificates for the entity based in part on the key tree leaves, each of the two or more certificates for the entity being associated with a different leaf of the key tree leaves;
• and
• cause the two or more certificates to be provided to the entity.