# US 12,113,914 B2 · Systems and methods for enforcing cryptographically secure actions in public, non-permissioned blockchains using bifurcated self-executing programs comprising shared digital signature requirements > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,113,914 B2 - Document ID: US12113914B2 - Status: Granted - Kind: B2 - Application number: 18/465,942 - Filed: 2023-09-12 - Published: 2024-06-06 - Granted: 2024-10-08 - Earliest claimed: 2022-12-06 - Assignees: Citibank, N.A. - Applicants: Citibank, N.A. - Inventors: Shishir Singh; Jonathan Miles Collin Rosenoer; Andres Wolberg-Stok; Biser Dimitrov - Web page: https://patentgrep.com/patent/US12113914B2 ## CPC - H04L 9/3247: {involving digital signatures} - H04L 9/3252: {using DSA or related signature schemes, e.g. elliptic based signatures, ElGamal or Schnorr schemes} - H04L 9/0825: {using asymmetric-key encryption or public key infrastructure [PKI], e.g. key signature or public key certificates} - H04L 9/3255: {using group based signatures, e.g. ring or threshold signatures} - H04L 9/3263: {involving certificates, e.g. public key certificate [PKC] or attribute certificate [AC]; Public key infrastructure [PKI] arrangements (network architectures or network communication protocols for supporting authentication of entities using certificates in a packet data network H04L63/0823)} - H04L 9/50: {using hash chains, e.g. blockchains or hash trees} - H04L 2209/46: Secure multiparty computation, e.g. millionaire problem - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract Systems and methods for a bifurcated self-executing program that wraps a first self-executing program (e.g., a first smart contract) on a blockchain within a second self-executing program (e.g., a second smart contract), in which the second self-executing program enforces the digital signature requirement. The bifurcated self-executing program comprises a single compiled self-executing program that combines the first self-executing program and the second self-executing program. ## Claims ### Claim 1 A system for conducting cryptographically secure actions in public, non-permissioned blockchains using a layer one blockchain solution featuring bifurcated self-executing programs that are compiled together and comprise shared digital signature requirements, the system comprising: a blockchain node for a cryptographically secure network, wherein the blockchain node comprises one or more processors; and a non-transitory computer-readable medium having instructions recorded thereon that, when executed by the one or more processors, cause operations comprising: receiving a first request, at a bifurcated self-executing program, to perform a first cryptographically secure blockchain action on the cryptographically secure network, wherein the first request has a first digital signature characteristic, and wherein the first digital signature characteristic comprises a variable defined in one or more lines of code of the bifurcated self-executing program, wherein the bifurcated self-executing program comprises a combination of a plurality of individual self-executing programs that cannot be altered once the bifurcated self-executing program is deployed; in response to receiving the first request, processing the first request with a first self-executing program of the bifurcated self-executing program, wherein the first self-executing program comprises a first function subset defined in the one or more lines of code of the bifurcated self-executing program; determining, based on the first self-executing program, whether the first digital signature characteristic corresponds to a digital signature requirement for the bifurcated self-executing program; and in response to determining that the first digital signature characteristic corresponds to the digital signature requirement, processing the first request with a second self-executing program of the bifurcated self-executing program to perform the first cryptographically secure blockchain action, wherein the second self-executing program comprises a second function subset defined in the one or more lines of code of the bifurcated self-executing program. ### Claim 2 A method for conducting cryptographically secure blockchain actions in public, non-permissioned blockchains using a layer one blockchain solution featuring bifurcated self-executing programs, the method comprising: receiving a first request, at a bifurcated self-executing program, to perform a first blockchain action, wherein the first request has a first digital signature characteristic, wherein the bifurcated self-executing program comprises a combination of a plurality of individual self-executing programs that cannot be altered once the bifurcated self-executing program is deployed; in response to receiving the first request, processing the first request with a first self-executing program of the bifurcated self-executing program; determining, based on the first self-executing program, whether the first digital signature characteristic corresponds to a digital signature requirement; and in response to determining that the first digital signature characteristic corresponds to the digital signature requirement, processing the first request with a second self-executing program of the bifurcated self-executing program to perform the first blockchain action. ### Claim 3 (depends on 2) The method of claim 2, wherein the digital signature characteristic comprises a signature based on an accountable subgroup multi-signature (ASM) scheme. ### Claim 4 (depends on 2) The method of claim 2, wherein the digital signature characteristic comprises a signature based on a Schnorr signature scheme. ### Claim 5 (depends on 2) The method of claim 2, wherein the digital signature characteristic comprises a signature based on a Boneh-Lynn-Shacham (BLS) digital signature scheme. ### Claim 6 (depends on 2) The method of claim 2, wherein determining whether the first digital signature characteristic corresponds to the digital signature requirement further comprises: determining a first signatory corresponding to the first digital signature characteristic; and determining whether the first signatory corresponds to an authorized signatory of a plurality of authorized signatories identified by the digital signature requirement. ### Claim 7 (depends on 2) The method of claim 2, wherein determining whether the first digital signature characteristic corresponds to the digital signature requirement further comprises: determining a first signature corresponding to the first digital signature characteristic; and determining whether the first signature corresponds to an approved Schnorr signature identified by the digital signature requirement. ### Claim 8 (depends on 4) The method of claim 4, wherein determining whether the first digital signature characteristic corresponds to the digital signature requirement further comprises: determining a prime number; determining a multiplicative group of integers modulo based on the prime number; and generating a group of approved Schnorr signatures based on the multiplicative group of integers modulo. ### Claim 9 (depends on 2) The method of claim 2, wherein determining whether the first digital signature characteristic corresponds to the digital signature requirement further comprises: determining a first signature corresponding to the first digital signature characteristic, wherein the first signature is based on a private key; and verifying the first signature based on a public key identified by the digital signature requirement. ### Claim 10 (depends on 2) The method of claim 2, wherein determining whether the first digital signature characteristic corresponds to the digital signature requirement further comprises: determining a first signature corresponding to the first digital signature characteristic, wherein the first signature is based on elements of an elliptic curve group; and verifying the first signature using a bilinear pairing. ### Claim 11 (depends on 2) The method of claim 2, wherein determining whether the first digital signature characteristic corresponds to the digital signature requirement further comprises: determining a first signature corresponding to the first digital signature characteristic by: receiving multiple signatures generated under multiple public keys for multiple messages; and aggregating the multiple signatures into the first signature; and determining whether the first signature corresponds to an approved signature identified by the digital signature requirement. ### Claim 12 (depends on 2) The method of claim 2, wherein the first digital signature characteristic is based on: receiving a first portion of a private key; receiving a second portion of the private key; and generating the first digital signature characteristic based on the first portion and the second portion. ### Claim 13 (depends on 2) The method of claim 2, wherein the digital signature requirement is based on: receiving a first contribution to a calculation of the digital signature requirement from a first user; receiving a second contribution to the calculation of the digital signature requirement from a second user; and calculating the digital signature requirement based on the first contribution and the second contribution. ### Claim 14 (depends on 2) The method of claim 2, wherein the first digital signature characteristic comprises a signature that is determined based on a private key, and wherein the digital signature requirement comprises a determination of authenticity, by a signature verifying algorithm, based on a public key and the signature. ### Claim 15 A non-transitory, computer-readable medium, comprising instructions that, when executed by one or more processors, cause operations comprising: receiving a first request, at a bifurcated self-executing program, to perform a first blockchain action, wherein the first request has a first digital signature characteristic, wherein the bifurcated self-executing program comprises a combination of a plurality of individual self-executing programs that cannot be altered once the bifurcated self-executing program is deployed; in response to receiving the first request, processing the first request with a first self-executing program of the bifurcated self-executing program; determining, based on the first self-executing program, whether the first digital signature characteristic corresponds to a digital signature requirement; and in response to determining that the first digital signature characteristic corresponds to the digital signature requirement, processing the first request with a second self-executing program of the bifurcated self-executing program to perform the first blockchain action. ### Claim 16 (depends on 15) The non-transitory, computer-readable medium of claim 15, wherein determining whether the first digital signature characteristic corresponds to the digital signature requirement further comprises: determining a first signatory corresponding to the first digital signature characteristic; and determining whether the first signatory corresponds to an authorized signatory of a plurality of authorized signatories identified by the digital signature requirement. ### Claim 17 (depends on 15) The non-transitory, computer-readable medium of claim 15, wherein determining whether the first digital signature characteristic corresponds to the digital signature requirement further comprises: determining a first signature corresponding to the first digital signature characteristic; and determining whether the first signature corresponds to an approved Schnorr signature identified by the digital signature requirement. ### Claim 18 (depends on 17) The non-transitory, computer-readable medium of claim 17, wherein determining whether the first digital signature characteristic corresponds to the digital signature requirement further comprises: determining a prime number; determining a multiplicative group of integers modulo based on the prime number; and generating a group of approved Schnorr signatures based on the multiplicative group of integers modulo. ### Claim 19 (depends on 15) The non-transitory, computer-readable medium of claim 15, wherein determining whether the first digital signature characteristic corresponds to the digital signature requirement further comprises: determining a first signature corresponding to the first digital signature characteristic, wherein the first signature is based on a private key; and verifying the first signature based on a public key identified by the digital signature requirement. ### Claim 20 (depends on 15) The non-transitory, computer-readable medium of claim 15, wherein determining whether the first digital signature characteristic corresponds to the digital signature requirement further comprises: determining a first signature corresponding to the first digital signature characteristic, wherein the first signature is based on elements of an elliptic curve group; and verifying the first signature using a bilinear pairing.