Across Protocol is the Fastest, Cheapest and Most Secure L2 to L1 Bridge.

It takes a long time for you to move funds from Layer 2s (like Arbitrum and Optimism) to Layer 1. It would be convenient if someone on L1 would just lend you the money for a small fee until the bridged funds arrived. You would have the experience of an instant transfer. The difficult part is doing this trustlessly.

Across Protocol solves this problem by insuring transactions. Individuals can profit by guaranteeing that the person lending the funds on L1 will actually send the loan.

It turns out that this method of cross-chain transfer is actually cheaper than other bridge solutions. It is faster, and we believe, more secure.

Across leverages UMA’s Optimistic Oracle (OO) to handle ‘insurance claims.’

When a transfer is initiated, the user sends the money on L2 via the canonical bridge to L1. An insurer on L1 pays out the transferred amount, less a fee, immediately. In order to become whole, the insurer then submits a claim to a liquidity pool on L1. This claim opens the dispute window, with the prompt of “Did the insurer fulfill her obligations and send the money to the recipient on L1?” So long as she did, the claims window will close after 2 hours and the insurer will be reimbursed.