Curriculum·Junior·J301
Chains, Layer 2s, and Bridges
The Nomad bridge, 1 August 2022. A routine upgrade to the implementation behind Nomad's Replica proxy contract passed 0x00 as a pre-approved trusted root, and 0x00 is also the value the contract returns for a message that was never proven, so every message submitted to the bridge was treated as already proven.
Lesson 1 opens on
Wintermute and Optimism, June 2022
The Optimism Foundation agreed to send 20 million OP tokens to the market maker Wintermute, which supplied a multisig address. Optimism sent two test transactions, Wintermute confirmed them, and the 20 million tokens followed. Wintermute then found it could not control them.
The lessons
- J301-01The scaling landscapeExplain what a rollup inherits from its base chain and what it does notabout 31 min · opens on Wintermute and Optimism, June 2022
- J301-02Alt-L1sIdentify what a chain gave up to obtain the throughput figure it advertisesabout 32 min · opens on The Solana halt, 14 September 2021
- J301-03Bridge architecturesClassify any bridge by how the destination chain learns what happened on the sourceabout 31 min · opens on Wormhole, 2 February 2022
- J301-04Bridge risk, specificallyState why a bridge's security is its smallest quorum rather than its averageabout 33 min · opens on Harmony Horizon bridge, June 2022
- J301-05When it goes wrongCompare recovery outcomes across documented bridge failures and identify what determined eachabout 34 min · opens on Poly Network, 10 August 2021
Labs
J301-L
Three bridges, three mechanisms
Move value across three ecosystems via three different mechanisms. Log cost, time, number of trust assumptions, and worst-case failure for each. Produce a comparison matrix.