The Cost of Secure Restaking vs. Proof-of-Stake
This work addresses capital efficiency in blockchain consensus mechanisms, providing theoretical insights for protocol designers, but it appears incremental as it builds on existing restaking and PoS concepts.
The paper compares capital efficiency between secure restaking and Proof-of-Stake protocols, deriving bounds on extra stakes needed for transformation and showing restaking savings can grow asymptotically as the square root of the number of validators.
We compare the total capital efficiency of secure restaking and Proof-of-Stake (PoS) protocols. First, we consider the sufficient condition for the restaking graph to be secure. The condition implies that it is always possible to transform such a restaking graph into separate secure PoS protocols. Next, we derive two main results: upper and lower bounds on the required extra stakes to add to the validators of the secure restaking graph to be able to transform it into secure PoS protocols. In particular, we show that the restaking savings compared to PoS protocols can be very large and can asymptotically grow as a square root of the number of validators. We also study a complementary question of aggregating secure PoS protocols into a secure restaking graph and provide matching lower and upper bounds on the PoS savings.