Publicação
Scalable low latency consensus for blockchains
| datacite.subject.fos | Departamento de Informática | pt_PT |
| dc.contributor.advisor | Bessani, Alysson Neves, 1978- | |
| dc.contributor.author | Avelãs, Diogo Miguel do Carmo | |
| dc.date.accessioned | 2022-07-11T08:22:06Z | |
| dc.date.available | 2022-07-11T08:22:06Z | |
| dc.date.issued | 2022 | |
| dc.date.submitted | 2021 | |
| dc.description | Tese de mestrado, Segurança Informática, Universidade de Lisboa; Faculdade de Ciências, 2022 | pt_PT |
| dc.description.abstract | State machine replication (SMR) is a classical technique to implement consistent and faulttolerant replicated services. This type of system is usually built on top of consensus protocols that have high throughput but have problems scaling to settings with a large number of participants or widearea sce narios due to the required number of messages exchanged to reach a consensus. We propose ProBFT (Probabilistic Byzantine Fault Tolerance), a consensus protocol specifically de signed to tackle the scalability problem of BFT protocols. ProBFT is a consensus protocol with optimal latency (three communication steps, as in PBFT) but with a reduced number of messages exchanged in each phase (O(n √ n) instead of PBFT’s O(n 2 )). ProBFT is a probabilistic protocol built on top of wellknown primitives, such as probabilistic Byzantine quorums and verifiable random functions, which provides high probabilities of safety and liveness when the overwhelming majority of replicas is correct. We also propose a state machine replication protocol called PROBER (PRObabilistic ByzantinE Replication) that builds on top of two consensus protocols, ProBFT and PBFT. PROBER makes use of ProBFT to provide fast and probabilistic replies to the clients and uses PBFT to eventually determinis tically commit the history of operations guaranteeing that the system will not roll back the requests after such commit. This periodic deterministic commit allows the clients to enjoy the low latency provided by ProBFT while still having the guarantees provided by a deterministic protocol. We provide a detailed description of both protocols and analyse the probabilities for safety and live ness depending on the current number of Byzantine replicas. | pt_PT |
| dc.identifier.tid | 202995160 | pt_PT |
| dc.identifier.uri | http://hdl.handle.net/10451/53743 | |
| dc.language.iso | eng | pt_PT |
| dc.subject | Consenso | pt_PT |
| dc.subject | Tolerância a faltas bizantinas | pt_PT |
| dc.subject | Quóruns probabilísticos | pt_PT |
| dc.subject | Replicação máquina de estados | pt_PT |
| dc.subject | Teses de mestrado - 2022 | pt_PT |
| dc.title | Scalable low latency consensus for blockchains | pt_PT |
| dc.type | master thesis | |
| dspace.entity.type | Publication | |
| rcaap.rights | openAccess | pt_PT |
| rcaap.type | masterThesis | pt_PT |
| thesis.degree.name | Tese de mestrado em Segurança Informática | pt_PT |