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3. PROBLEM DEFINITION

In cloud computing, all the user data are stored in the cloud resources. The results are
distributed to the user through the network when they needed. Most of the industrial data stored
in cloud computing, but cannot predict all stored data must have secured, hence most of cloud
data are encrypted. Even more encryption algorithm invented, sensitive information can leak if
that one key is leaked so, less secure. Most of the encryption key is managed by cloud providers,
so providers may break all information. This can bring considerable economic loss or severe
social reputation impairment to data owners.
As such, sharing or releasing privacy-sensitive data sets to third-parties in cloud will
bring about potential privacy concerns, and therefore requires strong privacy preservation. The
problems identified from the existing approaches are analyzed for privacy preserving and
scalability. Some importance will gave to the local recoding technique for the record linkage
attacks over the data sets.