Patent ID: 9077525
Filing Date: 2015-07-07
Classification: G06F,H04L

Abstract:
1. A method implemented by one or more computing devices, the method comprising: receiving an obfuscated policy at a cloud data management system, the obfuscated policy being a private version of a data-sharing policy specified by a user, the data-sharing policy regarding access by one or more data consumers to data about the user; receiving an obfuscated re-encryption program at the cloud data management system, the obfuscated re-encryption program having been generated using a private key of the user, a data consumer public key of an individual data consumer, and the obfuscated policy, wherein the cloud data management system does not have access to the private key of the user; receiving encrypted data at the cloud data management system from a data provider, the encrypted data being raw data about the user that has been encrypted using a user public key of the user; re-encrypting the encrypted data using the obfuscated re-encryption program and the obfuscated policy to obtain re-encrypted data; storing the re-encrypted data in the cloud data management system; receiving a modified obfuscated policy at the cloud data management system; receiving a modified obfuscated re-encryption program at the cloud data management system, the modified obfuscated re-encryption program having been generated using the private key of the user, the data consumer public key of the individual data consumer, and the modified obfuscated policy; receiving additional encrypted data from the data provider; and re-encrypting the additional encrypted data using the modified obfuscated re-encryption program instead of the obfuscated re-encryption program.