US 12,284,287 B2
Computer-implemented system and method providing a decentralised protocol for the recovery of cryptographic assets
John Fletcher, Cambridge (GB); and Silvia Bartolucci, London (GB)
Assigned to NCHAIN LICENSING AG, Zug (CH)
Filed by nChain Licensing AG, Zug (CH)
Filed on Oct. 16, 2023, as Appl. No. 18/380,645.
Application 18/380,645 is a continuation of application No. 17/833,391, filed on Jun. 6, 2022, granted, now 11,818,269.
Application 17/833,391 is a continuation of application No. 16/622,275, granted, now 11,356,263, issued on Jun. 7, 2022, previously published as PCT/IB2018/054104, filed on Jun. 7, 2018.
Claims priority of application No. 1709367 (GB), filed on Jun. 13, 2017.
Prior Publication US 2024/0048387 A1, Feb. 8, 2024
Int. Cl. H04L 29/06 (2006.01); H04L 9/06 (2006.01); H04L 9/08 (2006.01); H04L 9/30 (2006.01); H04L 9/32 (2006.01); H04L 9/00 (2022.01)
CPC H04L 9/3226 (2013.01) [H04L 9/0637 (2013.01); H04L 9/085 (2013.01); H04L 9/088 (2013.01); H04L 9/3066 (2013.01); H04L 9/3247 (2013.01); H04L 9/50 (2022.05); H04L 2209/56 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A computer-implemented method for enabling recovery of one or more digital assets held on a blockchain by a user under a public key Pk after a corresponding private key Sk for accessing the one or more digital assets is lost, the computer implemented method comprising:
setting access for the one or more digital assets held on the blockchain under the public key Pk and accessible using the corresponding private key Sk of the user such that the one or more digital assets are also accessible using a private key x shared by a congress on a blockchain network, the congress comprising a group of users on the blockchain network, each member of the congress having a private key share xi, the private key share xi to be used in a threshold signature scheme in which at least a threshold of private key shares must be used to generate a valid signature through a combination of partial signatures of the congress to access the one or more digital assets on behalf of the user, wherein setting access is initiated by a transaction Tl sent to the congress on the blockchain network indicating a desire to set up the recovery password RPw for accessing one or more digital assets held under the public key Pk, and wherein setting access comprises mapping data associated with the recovery password RPw to data associated with the private key x shared by the congress on the blockchain network, wherein the transaction Tl comprises metadata comprising recovery deposit data configured to request a recovery deposit upon a recovery attempt;
notifying, in response to the private key Sk being lost, the congress by the user to access the one or more digital assets using the threshold signature scheme on behalf of the user, the user proving their identity to the congress by providing the recovery password RPw and by providing a recovery deposit
detecting malicious activity by a malicious party in a congress, wherein the malicious party is one of the other members of the congress; and
confiscating at least a portion of digital assets previously transferred to the public group address by the malicious party.