Patent ID: 11909868
Assignee: IRONCORE LABS, INC.
Field: Digital communication (Electrical engineering)
Classification: CPC H  G | IPC G  H

Claim 9:
10. A method comprising:
encrypting data to a first group of users by encrypting a plaintext data using a randomly generated document encryption key (DEK) to form a ciphertext, then encrypting the DEK with a public key of the first group of users to form an encrypted DEK (EDEK);
adding a new user to the first group of users by computing a first transform key from the first group of users to the new user, and without re-encryption of data;
computing a second transform key from the new user to a computing device of the new user;
applying the first transform key to the EDEK to transform the EDEK into a transformed EDEK;
applying the second transform key to the transformed EDEK to transform the transformed EDEK into a doubly-transformed EDEK; and
decrypting the doubly-transformed EDEK via a private key for the computing device of the new user to retrieve the DEK; and
decrypting the ciphertext via the DEK to access the plaintext data.