SIP-204: Synth Teleporters

Simple Summary

Synth Teleporters allow Synths to be moved between different networks such as Ethereum and Optimism.

Abstract

Once the debt Synthesis is complete and all Synths are backed by SNX collateral across both L1 and Optimism it is possible to enable Synths to be transferred between networks. This SIP will deploy a set of contracts on both L1 and Optimism that can accept a Synth, burn it and then mint it on a destination network. It will also implement a system to pass messages about these events between the contracts on both networks.

Motivation

The majority of token bridges rely on one network being the "native" network for each token. This means when a token is bridged the destination network receives a "wrapped" version of the token, but the native token is still stored in a bridge contract on the source network. This is suboptimal because it requires securing the token bridge at all times in order for the the assets on the destination network to maintain their value. Most of these bridges rely on multisigs for security putting all of the assets on the destinateion network at risk. This approach is similar to how Circle must defened the USD in their bank account or risk USDC trading to zero, because each wrapped asset is always only as safe as the security of the bridge (multisig) on the source network. The Synth Teleporters do not rely on bridges to store assets on one chain and wrap them on another chain. They instead burn the assets on one network and mint them on the destination network. This ensures the total supply of each Synth remains constant without needing to secure two versions of the same asset. There are two ways to implement this system in terms of passing messages between networks, one relies on cross chain message protocols like those provided by chainlink a second option uses signed messages generated by the teleporter on each network that authorise the teleporter on the other side to mint the assets previously burned by the source Teleporter. Each of these implementations has trade-offs which will be discussed later in the rationale section of this SIP.

Specification

Overview

Teleporters will be deployed to all chains that support the Synthetix Exchange Contracts. They will read the available synths on that network to determine whether a Synth can be burned and teleported to the destination network. It is also possible that a teleport could be used to exchange Synths for teleportation to networks that do not currently support that Synth. While the initial deployment will support Optimism and L1, this network of teleports can be expanded to multiple networks. The most obvious first step being to support Polygon which is both firmly in the Ethereum ecosystem and has deep liquidity across many assets.

Rationale

This is where you explain the reasoning behind how you propose to solve the problem. Why did you propose to implement the change in this way, what were the considerations and trade-offs. The rationale fleshes out what motivated the design and why particular design decisions were made. It should describe alternate designs that were considered and related work. The rationale may also provide evidence of consensus within the community, and should discuss important objections or concerns raised during discussion.

Technical Specification

The technical specification should outline the public API of the changes proposed. That is, changes to any of the interfaces Synthetix currently exposes or the creations of new ones.

Test Cases

Test cases for an implementation are mandatory for SIPs but can be included with the implementation.

Configurable Values (Via SCCP)

Please list all values configurable via SCCP under this implementation.

Copyright

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