PoS: Economics
Yackolley Amoussou-Guenou, Bruno Biais, Maria Potop-Butucaru, Sara Tucci-Piergiovanni
Tarun Chitra
Giulia Fanti, Leonid Kogan, Sewoong Oh, Kathleen Ruan, Pramod Viswanath, Gerui Wang
"Rich getting richer" phenomenon
Equitability: how much the fraction of total stake belonging to a node can grow or shrink compared to the node’s initial investment
Alternative block reward function called the geometric reward function
Rainer Stütz (Austrian Institute of Technology), Peter Gaži (IOHK), Bernhard Haslhofer (Austrian Institute of Technology), Jacob Illium (Chainalysis)
Background: Stake distribution lag i.e., the gap between the present stake distribution and the one to select conesnsus nodes
E.g., Ouroboros (7 days), Ouroboros Praos/Genesis (10 days), Algorand (1 or 2 days)
Contribution: Empirical analysis
Use Chainanalysis's attribution data
Problem: No widely deployed PoS → Investigate PoW currencies (Bitcoin, Bitcoin Cash, Litecoin and Zcash)
Unusual stake-shift spikes due to hard forks trigger and exchange hacks
nrryuya.icon > An advantage of deposit-based PoS (e.g. Casper) is no concern like stake distribution lag!
Security
Suhyeon Lee and Seungjoo Kim (CIST)
Sarah Azouvi, George Danezis, and Valeria Nikolaenko (Facebook Calibra)
"Fainality layer similar to Casper"
Chain-based PoS
Incentive of validators to wait to accept a vote from a future slot
Slashing
Jonah Brown-Cohen (UC Berkeley) et.al.
Global/local predictability of block creation (parameterized by number of blocks before which nodes can predict) and vulnerability to "predictable" selfish mining and "undetectable" nothing at stake
"Penalize both" for predictable selfish mining
Michael Neuder, Daniel J. Moroz Rithvik Rao, David C. Parkesk
Predictable Selfish Mining
On-chain deal for an attacker who has a slashing evidence of a validator
Increases the incentive to compromise the private keys of validators
"Kicking others out"
Censorship on other validators to kick them out for more reward shares/attacks
Jean-Philippe Martin (self) and Eunjin (EJ) Jung (RationalMind)
Propose gatekeeping attack: An attacking cartel prevent newcomers from joining.
Solution: A strict order to decide a proposer, relies on hardware ID tokens to to mitigate Sybil attacks.