1. Data Integrity Proofs in Cloud Storage Sravan Kumar R, Ashutosh Saxena Communication Systems and Networks (COMSNETS), 2011 Third International Conference Cites:39 Presenter : 陳昱安 Date : 2014/12/8 1

2. Outline Introduction Related work A data integrity proof in cloud scheme Conclusion 2

3. Introduction (1/2) While developing proofs for data possession at untrusted cloud storage servers we are often limited by the resources at the cloud server as well as at the client. The scheme should be able to produce a proof without the need for the server to access the entire file or the client retrieving the entire file from the server. 3

4. Introduction (2/2) The problem is further complicated by the fact that the owner of the data may be a small device, like a PDA or a mobile phone, which have limited CPU power, battery power and communication bandwidth. 4

5. Related Work (1/2) 5

6. Related Work (2/2) 6

7. A data integrity proof in cloud scheme We present a scheme which does not involve the encryption of the whole data. We encrypt only few bits of data per data block thus reducing the computational overhead on the clients. In our data integrity protocol the verifier needs to store only a single cryptographic key and two functions which generate a random sequence. 7

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11. A data integrity proof in cloud scheme ……… Meta Data 11

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13. Conclusion (1/2) Our scheme was developed to reduce the computational and storage overhead of the client as well as to minimize the computational overhead of the cloud storage server. We also minimized the size of the proof of data integrity so as to reduce the network bandwidth consumption. 13

14. Conclusion (2/2) 14