Efficient post-quantum anonymous attestation with signature-based join protocol and unlimited signatures

A computer-implemented method, comprising:

• generating a set of cryptographic keys for attestation of group member devices and a set of leaf nodes in a sub-tree of a Merkle tree corresponding to the set of cryptographic keys;
• forwarding the set of leaf nodes to a group manager device;
• receiving, from the group manager device, a subset of intermediate nodes in the Merkle tree, the intermediate nodes being common to all available authentications paths through the Merkel tree for signatures originating in the sub-tree;
• and
• determining a cryptographic key that defines an authentication path through the Merkle tree, the authentication path comprising one or more nodes from the set of leaf nodes and one or more nodes from the intermediate nodes received from the group manager device.

A non-transitory computer-readable medium comprising instructions which, when executed by a processor, configure the processor to perform operations, comprising:

• storing a public key associated with a signing device in a computer-readable medium;
• generating a set of cryptographic keys for attestation of group member devices and a set of leaf nodes in a sub-tree of a Merkle tree corresponding to the set of cryptographic keys;
• forwarding the set of leaf nodes to a group manager device;
• receiving, from the group manager device, a subset of intermediate nodes in the Merkle tree, the intermediate nodes being common to all available authentications paths through the Merkel tree for signatures originating in the sub-tree;
• and
• determining a cryptographic key that defines an authentication path through the Merkle tree, the authentication path comprising one or more nodes from the set of leaf nodes and one or more nodes from the intermediate nodes received from the group manager device.