Method for re-keying an encrypted data file
AssigneeNEC Corporation
InventorGhassan Karame
Life of this patent
Estimating the term…
Abstract
A method for re-keying an encrypted data file, the data file being stored chunkwise on a storage entity (SE), data file chunks being encrypted with a global secret, and the method being performed by one or more computing devices, includes updating the global secret for encryption data for a data chunk to be re-keyed such that an output of a non-interactive oblivious key exchange is used to identify the private key of the data chunk to be re-keyed with a new private key, wherein the non-interactive oblivious key exchange uses an oblivious protocol; and reencrypting the data chunk to be re-keyed with the updated global secret.
Claims20
A method for re-keying an encrypted data file, the data file being stored chunkwise on a storage entity (SE), data file chunks being encrypted with a global secret, and the method being performed by one or more computing devices, the method comprising:
- updating the global secret for encryption data for a data chunk to be re-keyed such that an output of a non-interactive oblivious key exchange is used to identify a private key of the data chunk to be re-keyed with a new private key, wherein the non-interactive oblivious key exchange uses an oblivious protocol;
- and
- reencrypting the data chunk to be re-keyed with the updated global secret.
A system for re-keying an encrypted data file, comprising:
- a client (C),
- a storage entity (SE), and
- an assist server (AS),
- wherein the SE is adapted to store a data file being chunkwise,
- wherein the C is adapted to request re-keying of a data file chunk encrypted with a global secret and to reencrypt the data chunk with an updated global secret, and
- wherein the AS is adapted to update the global secret for encryption for the data chunk to be re-keyed, such that an output of a non-interactive oblivious key exchange is used to identify a private key of the chunk to be re-keyed with a new private key, wherein the non-interactive oblivious key exchange uses an oblivious protocol.
An assist server for re-keying an encrypted data file, the data file being stored chunkwise on a storage entity (SE), data file chunks being encrypted with a global secret, the assist server comprising:
- one or more processors;
- and
- a tangible, non-transitory computer-readable medium having instructions thereon which, upon being executed by the one or more processors, alone or in combination, provide for execution of a method comprising:
- updating the global secret for encryption data for a data chunk to be re-keyed such that an output of a non-interactive oblivious key exchange is used to identify a private key of the data chunk to be re-keyed with a new private key, wherein the non-interactive oblivious key exchange uses an oblivious protocol;
- and
- providing the updated global secret to a client (C), wherein the client reencrypts the data chunk to be re-keyed with the updated global secret.
Dependencies are inferred from the claim text.