Exploring GASPER and LMD-GHOST in Blockchain Consensus Protocols
Delve into the world of blockchain consensus with GASPER and LMD-GHOST, two innovative approaches combining safety and liveness properties. Learn about GHOST, Casper FFG, and the progress made in achieving probabilistic safety and liveness in distributed systems.
Download Presentation
Please find below an Image/Link to download the presentation.
The content on the website is provided AS IS for your information and personal use only. It may not be sold, licensed, or shared on other websites without obtaining consent from the author. Download presentation by click this link. If you encounter any issues during the download, it is possible that the publisher has removed the file from their server.
E N D
Presentation Transcript
Gasper - Combining GHOST & Casper Presentation by Sarisht Wadhwa Link to paper: https://arxiv.org/pdf/2003.03052.pdf
Asynchrony - Liveness and Termination FLP Impossibility https://groups.csail.mit.edu/tds/papers/Lynch/jacm85.pdf
Asynchrony - Liveness and Termination FLP Impossibility But We want All!!
Two Ghosts in the same trench-coat I can solve consensus with safety, but can t guarantee an output each time I can solve consensus with liveness, but can t be safe https://blog.ethereum.org/2020/02/12/validated-staking-on-eth2-2-two-ghosts-in-a-trench-coat/
Two Ghosts in the same trench-coat Ok Let s combine and do it all**
Organization of Presentation GHOST and its variants GASPER (GHOST+ CASPER FFG) Casper FFG Gasper: Combining both the ghosts GHOST (And Variants) Casper FFG
GHOST: Greediest Heaviest Observed SubTree VIEW of Validator L D G J M A B I K F C H E
LMD-GHOST: Latest Message Driven GHOST VIEW of Validator L D G J M A B I K F C H E
LMD-GHOST: Latest Message Driven GHOST VIEW of Validator L D G J M A B I K F C H E
GHOST Properties Probabilistic Safety Always Live
Progress GASPER (GHOST+ CASPER FFG) HLMD GHOST Casper FFG LMD-GHOST GHOST
Casper FFG Attestation Justification Justified Checkpoint Block A Checkpoint Block A Justified Checkpoint Block A
Casper FFG Attestation Justification Checkpoint Block A extends Justified Checkpoint block B Extend the last justified block in your attestation
Casper FFG Attestation Justification Attestation Justification Justified Checkpoint Block A Checkpoint Block B Checkpoint Block A extending B
Casper FFG Attestation Justification Attestation Justification Checkpoint Block B Checkpoint Block A extending B Checkpoint Block A What if no 2/3 Majority is reached in this round?
Casper FFG Attestation Justification Attestation Justification Checkpoint Block B Checkpoint Block A extending B Checkpoint Block A
Slashing height Block A Block B
Slashing height Block A Block B Beacon Chain
Slashing Block A0 Block B0 Block B1 Block A1
Slashing Block A0 Block B0 Block B1 Block A1 Beacon Chain
Casper FFG Properties Plausible Liveness Accountable Safety
Progress GASPER (GHOST+ CASPER FFG) HLMD-GHOST LMD-GHOST Slashing Casper FFG GHOST
Gasper Epoch 3 Epoch 0 Epoch 1 Epoch 2 1 2 3 4 6 9 10 11 12 5 7 8
Epoch Boundary Blocks and Pairs EBB - Epoch Boundary Block (Block, epoch) LEBB - Last Epoch Boundary Block
Blocks and attestations Block B Attestation A Slot(B) Parent(B) Slot(A) Block(A) Checkpoint Edge Accepted attestations Block Data
Progress GASPER (GHOST+ CASPER FFG) HLMD-GHOST LMD-GHOST Slashing Casper FFG GHOST
HLMD-GHOST: Hybrid Latest Message Driven GHOST VIEW of Validator x10000 A B L D G J M X A B I K F C H E Justified Block
Properties One epoch -> At-most one Justification, or ( ) Slashing of Stakes will happen Finalization: Block always included, or system is broken! Major slashing can happen in this case.
GASPER Properties Accountably Safety Always Live
Progress GASPER (GHOST+ CASPER FFG) HLMD-GHOST LMD-GHOST Slashing Casper FFG GHOST
