Aggelos Kiayias, Andrianna Polydouri, Dionysis Zindros
AFT '21
27th September, 2021
Simplified Payment Verification (SPV)
SPV protocol
Superlight clients
Ideal superblock distribution
Proof contains only some superblock headers...
Consensus Protocol changes
magic!
"Superblocks protocol can be deployed as-is under velvet fork"
False super-pointers could...
"Thorny" blocks
cut-and-paste portions of the honest chain
cut-and-paste portions of the honest chain
skip honest upgraded blocks of attacked level
honest miners ignore unupgraded and thorny blocks while updating the interlink
Suppression & Chainsewing
velvet honest majority assumption
simple chain quality does not suffice!
the adversary may attack only some superblocks...
Consensus rule update: MMR chain commitments
"FlyClient protocol can be deployed as-is under velvet fork"
Suppression & Chainsewing
andriannapolyd@gmail.com