US 10,372,918 B2Granted

Method for storing a data file of a client on a storage entity

AssigneeNEC Corporation

InventorsJens-Matthias Bohli, Ghassan Karame, Frederik Armknecht

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Abstract

A method for storing a data file of a client on a storage entity includes generating, by a proxy entity, a master encryption key; encrypting, by the client, the data file using the master encryption key to produce an encrypted file; computing a hash-tree for the encrypted file and using a top-hash of the hash-tree as a file identification (FID); and determining, by the proxy entity, whether the FID is already known to the storage entity. If the FID is not already known to the storage entity the method further includes computing, by the proxy entity, a top-hash of the encrypted file (PFID), and when the ownership of the data file has been proven, storing the FID being equal with the PFID at the client together with the hash value.

Claims15

Dependent claims

A method for storing a data file of a client on a storage entity, the method comprising:

a) generating, by a proxy entity, a master encryption key, wherein the master encryption key is a deterministic function of the data file based on a hash value of a hash-function performed on the data file,
b) encrypting, by the client, the data file using the master encryption key to produce an encrypted file,
c) computing a hash-tree for the encrypted file and using a top-hash of the hash-tree as a file identification (FID) for the encrypted file,
d) determining, by the proxy entity, whether the FID is already known to the storage entity,
e) if the FID is not already known to the storage entity:
uploading, by the client, the encrypted file to the storage entity and to the proxy entity,
computing, by the proxy entity, a top-hash of the encrypted file (PFID),
performing a proof-of-ownership procedure for the encrypted data file to be stored by comparing the FID with the PFID, and
when the ownership of the data file has been proven, storing the FID being equal with the PFID at the client together with the hash value, and
f) if the FID is already known to the storage entity:
performing a proof-of-ownership-procedure for the encrypted data file to be stored by comparing the FID with a prior computed FID, and
when the ownership of the data file has been proven, storing the FID at the client together with the hash value.

9 more elements

Dependencies are inferred from the claim text.

Facts

Application: 15/550,373Filed 13 Feb 2015
Published: US 2018/0025167 A125 Jan 2018
Granted: 6 Aug 2019
Term ends: Not estimatedThe source records don’t support an estimate.

Classification8 codes

G06F 21/602
Protecting data: providing cryptographic facilities or services
G06F 21/6218
Protecting access to data via a platform, e.g. using keys or access control rules: to a system of files or objects, e.g. local or distributed file…
H04L 9/0643
The encryption apparatus using shift registers or memories for block-wise or stream coding, e.g. DES systems or RC4; Hash functions;…
H04L 9/0861
Key distribution or management, e.g. generation, sharing or updating, of cryptographic keys or passwords: generation of secret information…

Family

US 2018/0025167 A1Pre-grant publication · published 25 Jan 2018
US 10,372,918 B2This patent

From the US filing history. Foreign family members aren’t listed.

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