FogDedupe: A Fog-Centric Deduplication Approach Using Multi-Key Homomorphic Encryption Technique

Algorithm 2

Fog node—identifying the redundant data chunks.

Input: Partial hash values (pα)

Output: Redundancy verification results.

Begin

    1.    Fog node receives the chunk id (C_id), file id (F_id), and hash values (pα)

        from the data owners.

    2.    Fog node identifies the location of each data chunk and stored it in the

        DIT.

    3.    Redundancy verification (incoming data chunks)

        If (all corresponding bit position of pα ==1)

        a.  Data chunk ← Duplicate data chunk

        b.  Create a tag to represent that the corresponding ciphertext of the

          data chunk is duplicate and the fog node prohibits the data owner

          from uploading redundant data to the cloud servers.

        c.  Sends tag to the data owner.

        Else (bit position (SIT) ==0 or bit position (SIT) == at least one 0)

        a.  Data chunk ← Non-duplicated data chunk

        b.  Calculate the percentage of non-zero hash bits in the index table.

        c.  Creates tag for the non-duplicated data chunk

        d.  Sends the non-duplicated tag to the data owner.

        e.  Sends the percentage of non-zero hash bits to the cloud admin.

End