2026-09-20T15:24:28Z https://www.ideals.illinois.edu/oai-pmh

oai:www.ideals.illinois.edu:2142/113237 2023-07-11 col_2142_5131 col_2142_8888 com_2142_5130 com_2142_8887 com_2142_234

Viswanath, Pramod Pan, Siheng 2022-01-12T22:51:33Z 2022-01-12T22:51:33Z 2024-01-12T22:56:20Z 2021-07-21 2021-08 Finality gadgets are comprised of a Byzantine Fault Tolerant (BFT) protocol finalizing blocks produced by a Proof-of-Work (PoW) or Proof-of-Stake (PoS) chain protocol. They have become very popular methods for combining the best features of the BFT and PoW protocols and are proposed for deployment in many major blockchains. While the finality gadget architecture has been explored through many distinct dimensions, their performance under an adversarial majority in the PoW chain protocol has received scant attention. The raison d’etre for a finality gadget is to provide safety even under an adversarial majority in the PoW chain (hence the term “finality” gadget). While safety guarantee is easily provided by the finality gadget, significant liveness vulnerabilities exist. The proposed remedy achieves asymptotic liveness but the achieved chain quality (the fraction of honest blocks in the ledger) and latency deteriorate exponentially as the adversary power increases beyond 50%. Furthermore, the proposed gadget does not guarantee liveness in protocols beyond the Nakamoto longest chain. In this thesis, we propose Advocate, a new finality gadget architecture, which achieves two main results: (a) optimal chain quality and low latency under a super-majority adversary for the Nakamoto longest chain protocol and (b) generalization to a variety of parallel-chain based scaling architectures, including OHIE, Prism and ledger combiner. We demonstrate via a full-stack implementation the robustness of Advocate under a 90% adversarial majority. Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2023-08-01 The student, Siheng Pan, accepted the attached license on 2021-07-20 at 16:05. The student, Siheng Pan, submitted this Thesis for approval on 2021-07-20 at 16:29. This Thesis was approved for publication on 2021-07-21 at 09:38. DSpace SAF Submission Ingestion Package generated from Vireo submission #16599 on 2022-01-12 at 13:02:53 Made available in DSpace on 2022-01-12T22:51:33Z (GMT). No. of bitstreams: 2 PAN-THESIS-2021.pdf: 520872 bytes, checksum: e8f0f073b3ca9a39f6ae1781f7053d1b (MD5) LICENSE.txt: 4207 bytes, checksum: f7cbe5f658d2283cf5b5207751cbd6d9 (MD5) Previous issue date: 2021-07-21 Embargo set by: Seth Robbins for item 121163 Lift date: 2024-01-12T22:51:46Z Reason: Author requested closed access (OA after 2yrs) in Vireo ETD system Embargo set by: Seth Robbins for item 121163 Lift date: 2024-01-12T22:53:32Z Reason: Author requested closed access (OA after 2yrs) in Vireo ETD system Embargo set by: Seth Robbins for item 121163 Lift date: 2024-01-12T22:54:14Z Reason: Author requested closed access (OA after 2yrs) in Vireo ETD system Embargo set by: Seth Robbins for item 121163 Lift date: 2024-01-12T22:55:09Z Reason: Author requested closed access (OA after 2yrs) in Vireo ETD system Embargo set by: Seth Robbins for item 121163 Lift date: 2024-01-12T22:56:20Z Reason: Author requested closed access (OA after 2yrs) in Vireo ETD system Author requested closed access (OA after 2yrs) in Vireo ETD system Limited application/pdf http://hdl.handle.net/2142/113237 en Copyright 2021 Siheng Pan Blockchain Checkpointing Prism Security for proof of work blockchains via checkpointing text Thesis Electrical & Computer Eng Electrical & Computer Engr University of Illinois at Urbana-Champaign Thesis M.S.