Patent ID: 11936773
Assignee: PENTA SECURITY INC.
Field: Digital communication (Electrical engineering)
Classification: CPC H | IPC H

Claim 5:
6. The method of claim 5, further comprising:
checking a withdrawal of subscription of the first subscriber terminal;
generating an updated master key;
encrypting an updated master key with the public key of the supplier terminal and providing the supplier terminal with an encrypted and updated master key encrypted with the public key of the supplier terminal and the data identifier to enable the supplier terminal to decrypt the encrypted and updated master key encrypted with the public key of the supplier terminal and derive the symmetric key based on the master key, the data identifier, and the key update count value; and
encrypting the updated master key with the public key of the second subscriber terminal and providing the second subscriber terminal with an encrypted and updated master key encrypted with the public key of the second subscriber terminal and the data identifier to enable the second subscriber terminal to decrypt the encrypted and updated master key encrypted with the public key of the second subscriber terminal and derive the symmetric key based on the master key, the data identifier, and the key update count value.