# US 2019/0319801 A1 · Efficient post-quantum anonymous attestation with signature-based join protocol and unlimited signatures > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0319801 A1 - Document ID: US20190319801A1 - Status: Published application - Kind: A1 - Application number: 16/455,978 - Filed: 2019-06-28 - Published: 2019-10-17 - Earliest claimed: 2019-06-28 - Assignees: Intel Corporation - Applicants: Intel Corporation - Inventors: MANOJ SASTRY; RAFAEL MISOCZKI - Web page: https://patentgrep.com/patent/US20190319801A1 ## CPC - H04L 9/3247: {involving digital signatures} - H04L 9/0643: {Hash functions, e.g. MD5, SHA, HMAC or f9 MAC} - H04L 9/0822: {using key encryption key} - H04L 9/0894: {Escrow, recovery or storing of secret information, e.g. secret key escrow or cryptographic key storage} - H04L 9/3236: {using cryptographic hash functions} - H04L 9/3239: {involving non-keyed hash functions, e.g. modification detection codes [MDCs], MD5, SHA or RIPEMD} - H04L 9/0861: {Generation of secret information including derivation or calculation of cryptographic keys or passwords} - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract In one example an apparatus comprises a computer readable memory; and a signature module to generate 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, forward the set of leaf nodes to a group manager device, receive, 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 determine 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. Other examples may be described. ## Claims ### Claim 1 An apparatus, comprising: a computer readable memory; a signature module to: generate 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; forward the set of leaf nodes to a group manager device; receive, 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 determine 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. ### Claim 2 (depends on 1) The apparatus of claim 1, the signature module to: generate a signature of a message using a one-time private key and the at least one authentication path through the Merkle tree. ### Claim 3 (depends on 2) The apparatus of claim 2, the signature module to: determine the signature using a set of cryptographic keys that defines the authentication path through the Merkle tree. ### Claim 4 (depends on 3) The apparatus of claim 3, wherein to generate the set of cryptographic keys comprises to determine a number of cryptographic keys to generate based at least in part on a number of leaf nodes assigned to each member compute device of the group in a Merkle-based signature scheme. ### Claim 5 (depends on 1) The apparatus of claim 1, further comprising a cryptographic module to generate a cryptographic hash of each of one or more of the cryptographic keys of the set of cryptographic keys. ### Claim 6 (depends on 5) The apparatus of claim 5, wherein to generate the set of cryptographic keys comprises to generate one or more asymmetric key pairs, wherein each asymmetric key pair includes a public cryptographic key and a corresponding private cryptographic key. ### Claim 7 (depends on 5) The apparatus of claim 5, wherein to generate the cryptographic hash of each of the one or more cryptographic keys comprises to generate a cryptographic hash of the public cryptographic key of each symmetric key pair. ### Claim 8 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. ### Claim 9 (depends on 8) The method of claim 8, further comprising: generating a signature of a message using a one-time private key and the at least one authentication path through the Merkle tree. ### Claim 10 (depends on 9) The method of claim 9, further comprising: determining the signature using a set of cryptographic keys that defines the authentication path through the Merkle tree. ### Claim 11 (depends on 10) The method of claim 10, wherein generating the set of cryptographic keys comprises to determine a number of cryptographic keys to generate based at least in part on a number of leaf nodes assigned to each member compute device of the group in a Merkle-based signature scheme. ### Claim 12 (depends on 11) The method of claim 11, further comprising generating a cryptographic hash of each of one or more of the cryptographic keys of the set of cryptographic keys components to determine a root node value of the Merkle tree. ### Claim 13 (depends on 12) The method of claim 12, wherein generating the set of cryptographic keys comprises generating one or more asymmetric key pairs, wherein each asymmetric key pair includes a public cryptographic key and a corresponding private cryptographic key. ### Claim 14 (depends on 12) The method of claim 12, wherein generating the cryptographic hash of each of the one or more cryptographic keys comprises generating a cryptographic hash of the public cryptographic key of each symmetric key pair. ### Claim 15 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. ### Claim 16 (depends on 15) The non-transitory computer-readable medium of claim 15, further comprising instructions which, when executed by the processor, configure the processor to perform operations, comprising: generating a signature of a message using a one-time private key and the at least one authentication path through the Merkle tree. ### Claim 17 (depends on 16) The non-transitory computer-readable medium of claim 16, further comprising instructions which, when executed by the processor, configure the processor to perform operations, comprising: determining the signature using a set of cryptographic keys that defines the authentication path through the Merkle tree. ### Claim 18 (depends on 17) The non-transitory computer-readable medium of claim 17, wherein generating the set of cryptographic keys comprises determining a number of cryptographic keys to generate based at least in part on a number of leaf nodes assigned to each member compute device of the group in a Merkle-based signature scheme. ### Claim 19 (depends on 18) The non-transitory computer-readable medium of claim 18, further comprising instructions which, when executed by the processor, configure the processor to perform operations, comprising: generating a cryptographic hash of each of one or more of the cryptographic keys of the set of cryptographic keys. ### Claim 20 (depends on 19) The non-transitory computer-readable medium of claim 19, further comprising instructions which, when executed by the processor, configure the processor to perform operations, comprising: generating one or more asymmetric key pairs, wherein each asymmetric key pair includes a public cryptographic key and a corresponding private cryptographic key. ### Claim 21 (depends on 19) The non-transitory computer-readable medium of claim 19, further comprising instructions which, when executed by the processor, configure the processor to perform operations, comprising: generating a cryptographic hash of the public cryptographic key of each symmetric key pair.