#Layer2

Lichen is a research design for a single-issuer layer 2 that aims to let users recover bitcoin through an onchain dispute process when the issuer will not cooperate. Users and the issuer lock funds separately, with redemption rights subject to an agreed capacity. Tokens above that limit still require the issuer's cooperation.

The design continues to depend on the sequencer recording state correctly; malicious sequencing can cause losses. The newsletter also covers a proposal to store known hash preimages in output descriptors. These secrets should be backed up and protected like keys, and excluded from public descriptors.

Ethereum layer-2 networks aim to handle more activity outside the mainnet while using its settlement or data capabilities. Rollups, for example, execute transactions on another layer and submit relevant data or results to Ethereum, spreading costs across multiple operations. This helps explain why L2 networks can offer lower fees.

L2 is not a single product: networks differ in technology, smart contracts and maturity. The source notes that networks claiming to scale Ethereum do not necessarily use the same security model, and there is no single official L2.