state_root: 0x7f... finality: 12min throughput: 4,000 tps
A chrome-and-clay knowledge vessel for rollups, proofs, bridges, channels, settlement, and the beautiful incompleteness of scaling systems.
progressive disclosure archive
Layer 2 is not a single mechanism. It is a sedimentary stack of assumptions: execution elsewhere, proof somewhere, data availability nearby, settlement below. Each node in this wiki opens once, then remains as accumulated context.
Optimistic Rollups post transaction data to Layer 1 and rely on challenge periods to expose invalid state transitions. Their confidence is social and temporal: anyone may inspect the repaired seam before finality hardens.
ZK Rollups compress execution into validity proofs. Instead of waiting for disputes, they present cryptographic evidence that the new state follows from the old one. The seam is smaller, brighter, and harder to forge.
Fraud proofs assume correctness until challenged; validity proofs demand mathematical evidence up front. Neither is morally superior. They choose different locations for latency, computation, decentralization, and user confidence.
Terms like zk-SNARKs, STARKs, and interactive fraud games are not ornaments. They are load-bearing ceramics in the architecture of scale.
A bridge is a promise that state observed in one context can be honored in another. Canonical bridges inherit the parent chain's settlement path; external bridges add committees, liquidity, and new fracture points.
The wiki treats bridge risk as geological: custody, message verification, upgrade keys, liquidity depth, and exit latency are separate strata that can slide under pressure.
State channels lock a shared starting condition on Layer 1, then let participants exchange signed updates privately. The chain is invoked only to open, close, or arbitrate. This makes channels intimate, fast, and topology-dependent.
They are less a universal scaling layer than a set of precise instruments: excellent for repeated bilateral or small-group interaction, awkward for global liquidity and arbitrary composability.
Layer 2 systems borrow security by periodically rooting claims into Layer 1. The root may be a state commitment, a proof verification, a posted data blob, or an exit game. Settlement is the moment a temporary surface becomes historical sediment.
Understanding a protocol means asking: what is posted, who can verify it, what data must remain available, and how can users leave if the operator disappears?
Data Availability The guarantee that transaction data needed to reconstruct state can be retrieved.
Sequencer The entity ordering transactions before they are committed to the base layer.
Exit Window Time preserved for users to withdraw or challenge before final settlement.
Shared Security Protection borrowed from another chain's validator or proof-verification system.