A Blockchain-based Flight Data Recorder for Cloud Accountability - PowerPoint PPT Presentation

A Blockchain-based Flight Data Recorder for Cloud Accountability G. D’Angelo, S. Ferretti , M. Marzolla Dept. of Computer Science and Engineering s.ferretti@unibo.it

Cloud Computing On-demand self service On-demand self service On-demand self service Broad network access Resource pooling Rapid elasticity Measured service

Cloud Computing Reliability On-demand self service On-demand self service On-demand self service Broad network access Resource pooling Rapid elasticity Measured service

Cloud Computing Reliability On-demand self service On-demand self service On-demand self service Broad network access Availability Resource pooling Rapid elasticity Measured service

Cloud Computing Reliability On-demand self service On-demand self service On-demand self service Broad network access Availability Resource pooling Rapid elasticity Accountability Measured service

Cloud Computing User Domain Alice

Cloud Computing User Domain Service Domain Bob Alice

Cloud Computing User Domain Service Domain Bob, please handle my data Bob Alice

Cloud Computing User Domain Service Domain Bob Alice

Cloud Computing User Domain Service Domain Cloud Domain Bob Alice Carl

Cloud Computing User Domain Service Domain Cloud Domain Carl, please hold my service and the data I have Bob Alice Carl

Cloud Computing User Domain Service Domain Cloud Domain Bob Alice Carl

Accountability User Domain Service Domain Cloud Domain Bob Alice Carl If something goes wrong, who is accounted?

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Blockchain as a Flight Data Recorder ● All operatjons accomplished in the cloud recorded in the blockchain

Blockchain as a Flight Data Recorder ● All operatjons accomplished in the cloud recorded in the blockchain ● Possible solutjons: • Double signed transactjons ● Certjfjes that two partjes agree on something ● Coarse method

Blockchain as a Flight Data Recorder ● All operatjons accomplished in the cloud recorded in the blockchain ● Possible solutjons: • Double signed transactjons ● Certjfjes that two partjes agree on something ● Coarse method • Logging (without smart contracts) ● Record all actjons ● SLA violatjons verifjed through the need of an arbitrator

Blockchain as a Flight Data Recorder ● All operatjons accomplished in the cloud recorded in the blockchain ● Possible solutjons: • Double signed transactjons ● Certjfjes that two partjes agree on something ● Coarse method • Logging (without smart contracts) ● Record all actjons ● SLA violatjons verifjed through the need of an arbitrator • Logging with smart contracts ● Smart contract acts as the arbitrator

File Upload Operation S u User P u Blockchain S c Cloud P c

File Upload Operation S u User P u upload req init Blockchain S c Cloud P c

File Upload Operation S u User P u upload req init Blockchain upload ACK S c Cloud P c

File Upload Operation S u User P u upload transfer req init S u Blockchain upload ACK S c Cloud P c

File Upload Operation S u User P u upload transfer req init S u Blockchain transfer upload ACK ACK S c digest Cloud P c

File Upload Operation S u User P u digest upload transfer ACK / NACK req init S u Blockchain transfer upload ACK ACK S c digest Cloud P c

File Delete S u User P u Blockchain S c Cloud P c

File Delete S u User P u delete req Blockchain S c Cloud P c

File Delete S u User P u delete req Blockchain delete ACK S c Cloud P c

Read (found) S u User P u Blockchain S c Cloud P c

Read (found) S u User P u read req Blockchain S c Cloud P c

Read (found) S u User P u read req Blockchain publish URL (encrypted data) S c Cloud P c

Read (found) S u User P u read read req S u Blockchain publish URL (encrypted data) S c Cloud P c

Read (missing) S u User P u Blockchain Smart Contract S c Cloud P c

Read (missing) S u User P u read req Blockchain Smart Contract S c Cloud P c

Read (missing) S u User P u read req Blockchain Smart Contract missing S c Cloud P c

Read (missing) S u User P u violatjon read check req req Blockchain Smart Contract missing S c Cloud P c

Read (missing) S u User P u violatjon read check req req Blockchain violatjon response Smart Contract missing S c Cloud P c

Concluding Considerations ● Blockchain as a fmight data recorder for Cloud accountability • Pseudo-anonymous and tamper-proof logging of events • Ledger used to verify if SLAs are violated • Self-enforcing smart contracts allow to automatjcally identjfy responsibilitjes and setule disputes ● Effjciency issues: • Current blockchains might not provide a short tjme responses • Transactjon fees might represent an economic disincentjve ● Lightweight, permissioned blockchains might be more performant, scalable, and only accessible by a dedicated group of entjtjes

Stefano Ferretti s.ferretti@unibo.it Department of Computer Science and Engineering University of Bologna Mura A. Zamboni 7 40127, Bologna Italy www.cs.unibo.it/sferretu