Abstract
How to audit outsourced data in centralized storage like cloud is well-studied, but it is largely under-explored for the rising decentralized storage network (DSN) that bodes well for a billion-dollar market. To realize DSN as a usable service in a fully decentralized manner, the blockchain comes in handy — to record and verify audit trails in forms of proof of storage, and based on that, to enforce fair payments with necessary dispute resolution.
Leaving the audit trails on the blockchain offers transparency and fairness, yet it 1) sacrifices privacy, as they may leak information about the data under audit, and 2) overwhelms on-chain resources, as they may be practically large in size and expensive to verify. Prior auditing designs in centralized settings are not directly applicable here. A handful of proposals targeting DSN cannot satisfactorily address these issues either.
We present an auditing solution that addresses on-chain privacy and efficiency, from a synergy of homomorphic linear authenticators with polynomial commitments for succinct proofs, and the sigma protocol for provable privacy. The solution results in, per audit, 288-byte proof written to the blockchain, and constant verification cost. It can sustain long-term operation and easily scale to thousands of users on Ethereum.
Leaving the audit trails on the blockchain offers transparency and fairness, yet it 1) sacrifices privacy, as they may leak information about the data under audit, and 2) overwhelms on-chain resources, as they may be practically large in size and expensive to verify. Prior auditing designs in centralized settings are not directly applicable here. A handful of proposals targeting DSN cannot satisfactorily address these issues either.
We present an auditing solution that addresses on-chain privacy and efficiency, from a synergy of homomorphic linear authenticators with polynomial commitments for succinct proofs, and the sigma protocol for provable privacy. The solution results in, per audit, 288-byte proof written to the blockchain, and constant verification cost. It can sustain long-term operation and easily scale to thousands of users on Ethereum.
| Original language | English |
|---|---|
| Title of host publication | Proceedings - 2020 IEEE 40th International Conference on Distributed Computing Systems |
| Subtitle of host publication | ICDCS 2020 |
| Publisher | IEEE |
| Pages | 201-211 |
| ISBN (Electronic) | 9781728170022 |
| ISBN (Print) | 9781728170039 |
| DOIs | |
| Publication status | Published - Nov 2020 |
| Event | 40th IEEE International Conference on Distributed Computing Systems (ICDCS 2020) - Virtual, Singapore Duration: 29 Nov 2020 → 1 Dec 2020 Conference number: 40 https://icdcs2020.sg/ |
Publication series
| Name | |
|---|---|
| ISSN (Print) | 1063-6927 |
| ISSN (Electronic) | 2575-8411 |
Conference
| Conference | 40th IEEE International Conference on Distributed Computing Systems (ICDCS 2020) |
|---|---|
| Abbreviated title | ICDCS'20 |
| Place | Singapore |
| Period | 29/11/20 → 1/12/20 |
| Internet address |