# US 11,444,755 B2 · Doubly-encrypted secret parts allowing for assembly of a secret using a subset of the doubly-encrypted secret parts > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,444,755 B2 - Document ID: US11444755B2 - Status: Granted - Kind: B2 - Application number: 16/595,004 - Filed: 2019-10-07 - Published: 2020-04-16 - Granted: 2022-09-13 - Earliest claimed: 2018-10-12 - Assignees: tZERO IP, LLC - Applicants: tZERO IP, LLC - Inventors: Stephen Christensen; Denny Becker; Tron Black; Michael Calcano; Tyler Perkins - Web page: https://patentgrep.com/patent/US11444755B2 ## CPC - H04L 9/085: {Secret sharing or secret splitting, e.g. threshold schemes} - H04L 9/0894: {Escrow, recovery or storing of secret information, e.g. secret key escrow or cryptographic key storage} - H04L 9/14: using a plurality of keys or algorithms - H04L 9/30: Public key, i.e. encryption algorithm being computationally infeasible to invert or user's encryption keys not requiring secrecy - H04L 9/3073: {involving pairings, e.g. identity based encryption [IBE], bilinear mappings or bilinear pairings, e.g. Weil or Tate pairing} - H04L 9/3239: {involving non-keyed hash functions, e.g. modification detection codes [MDCs], MD5, SHA or RIPEMD} - H04L 9/3252: {using DSA or related signature schemes, e.g. elliptic based signatures, ElGamal or Schnorr schemes} - H04L 9/3255: {using group based signatures, e.g. ring or threshold signatures} - H04L 9/3297: {involving time stamps, e.g. generation of time stamps} - H04L 9/50: {using hash chains, e.g. blockchains or hash trees} - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract A system includes at least one processor and at least one memory communicatively coupled to the at least one processor. The at least one processor is configured to encrypt each secret part of at least one set of secret parts into a corresponding singly-encrypted secret part. The at least one processor is also configured to encrypt each corresponding singly-encrypted secret part into a corresponding doubly-encrypted secret part using a corresponding at least one public key, each public key belonging to a corresponding one of at least one public/private keypair. At least a subset of the secret parts of the at least one set of secret parts are used to reconstruct a secret. ## Claims ### Claim 1 A system comprising: at least one processor; and at least one memory communicatively coupled to the at least one processor; wherein the at least one processor is configured to: encrypt each corresponding secret part of at least one set of secret parts into a corresponding singly-encrypted secret part by exclusive ORing (XORing) each secret part with at least one corresponding symmetric key to produce the corresponding singly-encrypted secret part; encrypt each corresponding singly-encrypted secret part into a corresponding doubly-encrypted secret part using a corresponding at least one public key, the corresponding at least one public key belonging to a corresponding one of at least one public/private keypair; wherein each corresponding doubly-encrypted secret part is distributed to a respective part holder of a plurality of part holders; and wherein two or more doubly-encrypted secret parts are received from two or more part holders of the plurality of part holders; wherein the two or more doubly-encrypted secret parts are used to reconstruct a secret. ### Claim 2 (depends on 1) The system of claim 1, wherein the at least one corresponding symmetric key for a first secret part and a second secret part is identical. ### Claim 3 (depends on 1) The system of claim 1, wherein the at least one corresponding symmetric key for a first secret part and a second secret part is distinct. ### Claim 4 (depends on 1) The system of claim 1, wherein each corresponding singly-encrypted secret part is encrypted using a single public key, the single public key belonging to a single public/private keypair; wherein the single public/private keypair also includes a corresponding private key. ### Claim 5 (depends on 1) The system of claim 1, wherein each doubly-encrypted secret part is encrypted using both at least one symmetric key and a public key belonging to the corresponding one of the at least one public/private keypair. ### Claim 6 (depends on 1) The system of claim 1, wherein each doubly-encrypted secret part is encrypted twice using a public key belonging to the corresponding one of the at least one public/private keypair. ### Claim 7 (depends on 1) The system of claim 1, wherein each doubly-encrypted secret part is encrypted using both at least one symmetric key and a corresponding part holder public key belonging to a corresponding part holder public/private keypair. ### Claim 8 A system comprising: at least one processor; and at least one memory communicatively coupled to the at least one processor; wherein the at least one processor is configured to: encrypt each corresponding secret part of at least one set of secret parts into a corresponding singly-encrypted secret part; encrypt each corresponding singly-encrypted secret part into a corresponding doubly-encrypted secret part using a corresponding at least one public key, the corresponding at least one public key belonging to a corresponding one of at least one public/private keypair; wherein two or more secret parts of the at least one set of secret parts are used to reconstruct a secret; decrypt at least one doubly-encrypted secret part into at least one singly-encrypted secret part using a corresponding at least one private key, the corresponding at least one private key belonging to a corresponding public/private keypair of the at least one public/private keypair; and re-encrypt each corresponding singly-encrypted part of the at least one singly-encrypted secret part using a corresponding second public key, the corresponding second public key belonging to a second public/private keypair. ### Claim 9 (depends on 8) The system of claim 8, wherein each secret part of the at least one set of secret parts is encrypted into the corresponding singly-encrypted secret part using at least one corresponding symmetric key. ### Claim 10 (depends on 8) The system of claim 8, wherein each secret part is encrypted into the corresponding singly-encrypted secret part using the corresponding at least one public key belonging to the corresponding one of the at least one public/private keypair. ### Claim 11 (depends on 8) The system of claim 8, wherein each doubly-encrypted secret part is encrypted using both at least one symmetric key and a public key belonging to the corresponding one of the at least one public/private keypair. ### Claim 12 (depends on 8) The system of claim 8, wherein each doubly-encrypted secret part is encrypted twice using a public key belonging to the corresponding one of the at least one public/private keypair. ### Claim 13 A system comprising: at least one processor; and at least one memory communicatively coupled to the at least one processor; wherein the at least one processor is configured to: encrypt each corresponding secret part of at least one set of secret parts into a corresponding singly-encrypted secret part; encrypt each corresponding singly-encrypted secret part into a corresponding doubly-encrypted secret part using a corresponding at least one public key, the corresponding at least one public key belonging to a corresponding one of at least one public/private keypair; wherein two or more secret parts of the at least one set of secret parts are used to reconstruct a secret; receive a plurality of doubly-encrypted secret parts; decrypt each corresponding doubly-encrypted secret part into the corresponding singly-encrypted secret part using a corresponding private key belonging to the corresponding one of the at least one public/private keypair; decrypt each corresponding singly-encrypted secret part into a corresponding secret part of a plurality of corresponding secret parts; and reconstruct the secret from a quantity of the plurality of corresponding secret parts, wherein the quantity is a second subset of a total number of secret parts previously created from the secret. ### Claim 14 (depends on 13) The system of claim 13, wherein each doubly-encrypted secret part is distributed to a respective part holder; wherein the plurality of doubly-encrypted secret parts are received from a plurality of part holders. ### Claim 15 (depends on 13) The system of claim 13, wherein each secret part of the at least one set of secret parts is encrypted into the corresponding singly-encrypted secret part using at least one corresponding symmetric key. ### Claim 16 (depends on 13) The system of claim 13, wherein each secret part of the at least one set of secret parts is encrypted into the corresponding singly-encrypted secret part using the corresponding at least one public key belonging to the corresponding one of the at least one public/private keypair. ### Claim 17 (depends on 13) The system of claim 13, wherein each doubly-encrypted secret part is encrypted using both at least one symmetric key and a public key belonging to the corresponding one of the at least one public/private keypair. ### Claim 18 (depends on 13) The system of claim 13, wherein each doubly-encrypted secret part is encrypted twice using a public key belonging to the corresponding one of the at least one public/private keypair. ### Claim 19 A system comprising: at least one processor; and at least one memory communicatively coupled to the at least one processor; wherein the at least one processor is configured to: encrypt each corresponding secret part of at least one set of secret parts into a corresponding singly-encrypted secret part; encrypt each corresponding singly-encrypted secret part into a corresponding doubly-encrypted secret part using a corresponding at least one public key, the corresponding at least one public key belonging to a corresponding one of at least one public/private keypair; wherein each doubly-encrypted secret part is distributed to a respective part holder of a plurality of part holders; wherein two or more doubly-encrypted secret parts are received from two or more part holders of the plurality of part holders; reconstruct a secret from the two or more doubly-encrypted secret parts, wherein the secret is a symmetric encryption key; and perform an action with the symmetric encryption key. ### Claim 20 (depends on 19) The system of claim 19, wherein the action comprises at least one of the following actions using the symmetric encryption key: encrypting first data; decrypting second data; generating a transaction address; or signing a transaction. ### Claim 21 (depends on 19) The system of claim 19, wherein each doubly-encrypted secret part is encrypted using both at least one symmetric key and a public key belonging to the corresponding one of the at least one public/private keypair. ### Claim 22 (depends on 19) The system of claim 19, wherein each doubly-encrypted secret part is encrypted twice using a public key belonging to the corresponding one of the at least one public/private keypair.