Ultralane

The initial problem with crypto payments was scalability and with the rollup-centric roadmap, the overall TPS capacity of ethereum has increased. Despite this, this has given rise to a lot of L2 networks.

Two people who are interested in transacting with each other over crypto will run into the following problems today:

• Slow bridging: Both use different L2 networks as their primary network according to their taste, hence to transact one of them has to bridge funds which is time-consuming and a bad experience.
• Fragmentation: To transact instantly, the user will have to hold funds on various networks which will cause fragmentation in their funds which is very frustrating.
• Lack of Privacy: Existing solutions require both sender and receiver to opt into the privacy solution. Hence this is also a reason for slow user privacy adoption.

Having personally frustrated with the above problems, we are proposing a solution that aims to solve the above three problems in crypto payments. Our features:

• Ultrafast: To solve slow bridging by taking user deposits in advance to pass the time for confirmations, instead of wasting user time like typical bridges that take user deposits when user actually needs to bridge.
• Crosschain: To solve user funds fragmentation by abstracting the idea of networks and just showing a single token balance.
• Privacy: To enable a user interested in keeping privacy while their peers use normal ethereum wallets like metamask.

Our solution is:

• optimistic that users funds are locked so we can sponsor the transaction immediately
• non-custodial and user can trigger trustless withdraw whenever they want
• uses create2 ethereum steath address to receive funds

We are using the following tech stack:

• Aztec Noir and their Solidity verifier
• Hyperlane
• Moonrepo manager
• USDC

Challenges we ran into:

• Pedersen and Posidon were slow in proving time like 50 seconds, so we are using nightly version of noir that comes with Poseidon2 which brought down the proving time to 7 seconds.
• Poseidon2 does not have solidity implementation so we wrote it ourselves.
• We also ran into issues while making crosschain messages as it requires ETH in the contract