This document was created as part of a technical challenge for a Blockchain Researcher position.
The time dedicated to this work was ~3.5 days of full-time effort, with 1 day of a pure research phase and the remaining time spent combining research with document elaboration.
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Analyze the most relevant web3 bridges. For each, compare each of the following:
- Security
- Decentralization
- Trust assumptions
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Design:
- How would you design an ideal bridge from scratch in a world where gas is free?
- How would you design a bridge from scratch in a world where gas is extremely expensive (in L1 only)?
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Modeling:
- Cost of attacking a bridge with minting rights and the potential profit for the attacker.
Along this document, certain trust assumptions are considered common to all bridges given the nature of the systems we are working with. These are:
- Source and target domain consensus mechanisms (trust-minimized).
- Extremely unlikely security leaks in the software (protocol contracts, node implementations, etc.).
- Correctness of signature creation and verification systems.
[Not exhaustive list]
- "Understanding Blockchain Bridges: the Key to Interoperability in Web3" by Hiro
- "Bridges" by ethereum.org
- "The Interoperability Trilemma" by Arjun Bhuptani
- "Why the future will be multi-chain, but it will not be cross-chain" by Vitalik
- REKT Leaderboard
- DefiLlama Bridges
- L2Beat Bridges
- Wormhole Official Docs
- IBC Official Docs
- Hop Official Docs
- Hop V1 Whitepaper
- "Introducing Everclear: The First Clearing Layer" by Arjun Bhuptani
This was a timeboxed effort, and some elaborations were set aside to prioritize creating a complete and deliverable version of the document. Some of the nice-to-have elaborations that were omitted are:
- Diagrams illustrating the architecture and functionality of the analyzed bridges.
- Greater detail and thoroughness in the descriptions of analyzed bridges' protocols.