Anduro: Sidechain Network

marathon announced yesterday Their Anduro Layer 2 proposal. There are actually no fundamentally new parts or developments in the Anduro design, but it is structured in a slightly different way compared to other existing sidechain systems such as RSK or Liquid/Elements.

Anduro is a federated model that utilizes a quorum, referred to as “Collective” in its published documentation. The key difference between Anduro and other sidechain proposals is its explicit design, which is based on collective operations and allows spinning and managing multiple sidechains with different architectures. This is not much different from the concept of DriveChain, which enables a wider sidechain network rather than a single network.

Anduro will be merge-mined just like RSK (which also uses a federation peg), and will not provide any type of additional security for Bitcoins pegged to federation-held sidechains. However, like RSK, it provides POW security for other assets that are not locked to the mainchain and can be issued on federation-managed sidechains.

Peg and consensus model

The actual peg between the mainchain and sidechain is basically the same as Liquid, and in terms of structure and implementation details, it appears to be almost identical. The Collective will start with 15 members, the entity that actually handles the multi-signature keys involved in managing the peg, and 50+ contributors similar to members of the Liquid portion who can accept and initiate withdrawals from sidechains. ) even if you do not actively participate in the withdrawal processing.

Like Liquid, Anduro uses a formal organization to handle governance issues. This means that it handles network upgrades, determines future changes to the Federation’s membership set, and generally determines all matters that will arise regarding the operation of the sidechains operated by the Collective. Even though the Federation is comprised of honest members, its security ultimately relies on the diversity of its jurisdictions to remain safe from any type of censorship resistance or confiscation of funds.

The interesting design part here is that, unlike RSK, the Collective takes an active role in the consensus process beyond facilitating the operation of the peg mechanism. In Anduro, the Collective actually reaches consensus on the content of blocks on a sidechain through the Byzantine Fault Tolerant (BFT) algorithm, or round-robin selection, where a single member constitutes the block for that round. It also periodically signs blocks to act as a checkpoint system to prevent any past entries from being reordered. Once signing and checkpointing are complete, miners cannot reconstruct sidechain blocks without the collective’s help.

These two elements essentially act as a firewall between miners and extractable value opportunities. MEV is any opportunity available to miners through reorder transactions, such as advance orders on decentralized exchanges, that can give miners the opportunity to earn additional profits when they mine the next block. MEV has shown a tendency to increase centralization pressure on block producers from other prevalent networks. Due to the fact that the Collective actually decides the content of the sidechain blocks, and miners simply commit to this through proof-of-work, the Collective takes on the role of actual block creation, acting as a shield against centralizing pressure on block producers (or miners in the case of Bitcoin). Do it.

Long term Marathon plans to work towards a trustless peg mechanism and consensus mechanism, citing BitVM in particular as an example of how this can be achieved. This calls into question the ability of the current architecture to maintain the MEV protections it has during this transition, but it also prevents the current MEV from presenting the risk of putting centralization pressure on miners. It is also important to note that BitVM, designed with a proof-verifier model, inherently requires defined participants to manage all funds locked in a BitVM peg. While it fundamentally improves the security model of a peg by allowing a single member to prove punishment for dishonest participants, completely eliminating the need for a federation equivalent would require large-scale changes to the design of BitVM itself.

Overall, the architecture strikes a good balance while implementing a variation of existing sidechain designs while intentionally creating a sort of protection layer between sidechains and miners regarding the risks of MEV.

first two

Anduro will support two sidechain architectures at launch. One is Bitcoin-based and the other is Ethereum-based.

Coordinate: Coordinate is a Bitcoin sidechain variant. We plan to implement small changes to Bitcoin, including native support for issuance of Liquid-like assets, and to accommodate Ordinal and token use cases such as BRC-20, as well as native DeFi products and services built around them.

Alys: Alys is an Ethereum sidechain variant that essentially ports the Ethereum Virtual Machine and Solidity to the Bitcoin sidechain. The hope is that it can provide a new learning curve environment for Ethereum application developers to focus on building services and tools on top of Bitcoin.