A cross-chain shielded pool utilizing zk-wormholes and confidential tokens for maximum anonymity.
All current privacy protocols such as RAILGUN and Privacy Pools require depositing assets in by calling their smart contract. This publicly broadcasts exactly which addresses are depositing into the pool, which asset they are depositing and how much of it as well as the TVL in the pool. These factors wildly affect the anonymity set.
What if all of those were no longer bottlenecks? Isekai is a privacy protocol inspired by EIP-7503 that enables cross-chain zk-wormholes for any asset. Instead of the depositor interacting with the contract directly, they instead send the funds to what looks like a normal EOA address which is secretly a hash of secret values that teleport those funds into the actual recipient's private balance in the shielded pool on any chain. That user can then either unshield or transact within the shielded pool. Since zk-wormholes look like any other normal token transfer, onlookers are unable to detect exactly who is depositing in the shielded pool, which token and amounts of each are being deposited, nor from which chain. It gains vastly stronger privacy and eliminates those previous bottlenecks.
Isekai provides 3 main values that have not been delivered by existing onchain privacy protocol applications.
ZK-Wormholes: a novel way inspired by EIP-7503 to teleport your assets into the shielded pool without broadcasting who is depositing in the pool onchain.
Chain abstraction: all chain states are synced and aggregated to a master pool that allows user to send funds from any chain to any chain with a simple fully private shielded transfer. Users do NOT need to withdraw there assets first to bridge them to another chain.
Privacy UX: signer delegation is used to allow one to transact on users' behalf within enforced permissions. This opens up opportunities to services like x402, subscriptions, payroll and others that require greater levels of privacy.
In addition, screeners are implemented to reject illicit funds from entering the shielded pool despite them not knowing which transfers are normal transfers and which are zk-wormholes. In other words, compliant privacy.
Any contract that inherits the interface can do zk-wormholes and participate in the shielded pool. This includes ERC20 tokens, NFTs, wrappers of existing assets, etc. This also means they will be cross-chain assets. Every transfer increases the anonymity set for all other assets and users.
<p>Signer delegation was built during this hackathon as a new feature. It allows a user to permit another wallet to spend their funds on their behalf within the shielded pool. This opens the door to new use-cases such as fully private recurring payments, trading and other programmable transactions that businesses and end-users can take advantage of.</p><p>To make it possible, a whole new zk circuit and smart contract had to be created to enable signer delegation logic in the shielded pool in a private way. No one sees the signer delegation info onchain. It is an EIP-712 signature verified within the zk circuit and applies granular permissions that restrict what the delegate signer can spend from user's assets within the shielded pool. To go a step further, another circuit for recursive proofs was also created to enable batch transaction of multiple delegated transfers within the shielded pool. This is a complemental optimization to save gas for delegates such as large subscription services or trading platforms handling high number of transactions.</p><p>A fully shielded marketplace was added to the app to showcase a use case possible by signer delegation. All trades are fully private and never leaves the shielded pool. Offerer asks for an asset in exchange for an asset in their shielded balance and grants the marketplace delegate spend permission to execute the trade on their behalf once a fulfiller accepts the offer. No information of this trade is leaked publicly onchain. The offerer and fulfiller do not even know who they are trading with since the delegate handle it. </p>
<p>Isekai has not raised any funds or started a funding round yet.</p>
