to ensure that the wrong server can be quickly indicated when Error Location: • data corruption is detected. Definitions of Our Auditing Scheme Our auditing scheme consists of procedures: Setup, Audit and Repair. Each procedure contains certain polynomial-time algorithms as follows: Setup: The data owner maintains this procedure to initialize the auditing scheme. (pk, This polynomial-time algorithm is run by the data owner KeyGen(1κ) sk): → to initialize its public and secret parameters by taking a security parameter as κ input. (x): This algorithm represents the interaction between the data Degelation(sk) → owner and proxy. The data owner delivers partial secret key to the proxy through x a secure approach. (sk, This polynomial time algorithm is run by the Sig And BlockGen F) t): → data owner and takes the secret parameter and the original file as input, and sk F then outputs a coded block set , an authenticator set _ and a file tag t. Audit: The cloud servers and TPA interact with one another to take a random sample on the blocks and check the data intactness in this procedure. (C): This algorithm is performed by the TPA with the → information of the file as input and a challenge as output. Finfo C ) (P): This algorithm is run by each cloud server with input ProofGen(C,_, → challenge coded block set and authenticator set _, then it outputs a proof C, P. (0, 1): This algorithm is run by TPA immediately after a proof Verify(P, pk, C) → is received. Taking the proof public parameter and the corresponding P, pk challenge as input, it outputs 1 if the verification passed and 0 otherwise. C Repair: In the absence of the data owner, the proxy interacts with the cloud servers during this procedure to repair the wrong server detected by the auditing process.
• Error Location: to ensure that the wrong server can be quickly indicated when data corruption is detected. Definitions of Our Auditing Scheme Our auditing scheme consists of procedures: Setup, Audit and Repair. Each procedure contains certain polynomial-time algorithms as follows: Setup: The data owner maintains this procedure to initialize the auditing scheme. KeyGen(1κ) → (pk, sk): This polynomial-time algorithm is run by the data owner to initialize its public and secret parameters by taking a security parameter κ as input. Degelation(sk) → (x): This algorithm represents the interaction between the data owner and proxy. The data owner delivers partial secret key x to the proxy through a secure approach. Sig And BlockGen (sk, F) → t): This polynomial time algorithm is run by the data owner and takes the secret parameter sk and the original file F as input, and then outputs a coded block set , an authenticator set _ and a file tag t. Audit: The cloud servers and TPA interact with one another to take a random sample on the blocks and check the data intactness in this procedure. → (C): This algorithm is performed by the TPA with the information of the file Finfo as input and a challenge C as output. ProofGen(C,_, ) → (P): This algorithm is run by each cloud server with input challenge C, coded block set and authenticator set _, then it outputs a proof P. Verify(P, pk, C) → (0, 1): This algorithm is run by TPA immediately after a proof is received. Taking the proof P, public parameter pk and the corresponding challenge C as input, it outputs 1 if the verification passed and 0 otherwise. Repair: In the absence of the data owner, the proxy interacts with the cloud servers during this procedure to repair the wrong server detected by the auditing process.
Auditing_for_Distributed_Storage_Systems.docx