Trust-less and Efficient Bridges via Random Sampling
summary
A protocol that verifies crosschain finality by asking a relayer who claims 2f+1 signatures to reveal a random sample of M signatures, reducing onchain cost while making attack probability exponential in M. Uses an extra BEY finality layer plus random sampling and dynamic sampling to counter relayer spamming, targets networks with ~300 validators, samples on the order of tens, and slashes misbehaving validators. A production bridge Snowbridge runs this and reports gas costs comparable to SNARK approaches.
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chapters (9)
- 0:00Trustless bridges intro
- 2:36Centralized relayer problems
- 4:28Trustless bridge requirements
- 6:58Light clients solution
- 8:43Random sampling in bridges
- 14:09Protocol technical details
- 17:45Security analysis
- 19:36Dynamic sampling counterattacks
- 21:23Status and future
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