Patent ID: 11930103
Assignee: VECHAIN GLOBAL TECHNOLOGY, S.AR.L
Field: Digital communication (Electrical engineering)
Classification: CPC H  G | IPC H

Claim 3:
4. A method of key management with a group of users, the group of users including an organizing primary user for creating the group of users and a primary user for splitting a transaction key, the method comprising:
obtaining, at a management device, group information about the group of users from a user device of the organizing primary user, the group information indicating at least the number of users in the group of users and a first predetermined value, the first predetermined value indicating the minimum number of users for restoring a transaction key, the group of users being used to manage the transaction key;
sending a message to a user device of the primary user for splitting the transaction key, wherein the message is related to a first one of the users in the group of users other than the primary user for splitting the transaction key, wherein the message indicates at least a public key of the first one of the users;
obtaining a plurality of sub-keys from the primary user for splitting the transaction key, the number of sub-keys being the same as the number of users in the group of users, wherein the plurality of sub-keys were generated by the primary user for splitting the transaction key by randomly generating the transaction key and then splitting the transaction key, the plurality of sub-keys being encrypted with public keys of the respective users;
caching the plurality of sub-keys for sending to the respective users;
in response to a registration request from a user device of a user in the group of users, sending signature data of the management device to the user device, the signature data comprising at least a random number signed by the management device;
determining, based on signature data from the user device, whether the user device is valid, the signature data being generated by signing the random number by the user device based on a private key preset in the user device in response to determining that the management device is valid; and
in response to determining that a user device of each user in the group of users is valid, determining that the group of users is valid.