Trustless Cardano Ethereum bridge

Market

Cardano is a next generation blockchain with fast, scalable, relatively low-cost transactions that is becoming increasingly attractive for decentralised application developers. One challenge that the Cardano ecosystem faces is liquidity. The Ethereum blockchain, having been created a number of years earlier and having a headstart in the developer community, is currently home to a majority of DeFi and NFT liquidity.

Cardano is attracting applications and liquidity, but these largely operate in isolation on the Cardano blockchain. There is a clear need for better integration of Cardano with other blockchain networks, in particular Ethereum, in order to enable seamless integration and bi-directional liquidity flows.

A number of early blockchain token bridges achieved security through decentralisation, but this is not enough. The bridge operators hold the keys and therefore the power to mint tokens out of thin air. There are better ways to solve this by building technically trustless bridges. Applied Blockchain is already building the "London Bridge' to integration the Algorand blockchain with Ethereum and others in the most secure way (using Intel SGX secure enclaves, and trustless proofs), and will extend London Bridge to integrate with Cardano.

Untenable fees have led to a liquidity migration from Ethereum, London Bridge will route that to Cardano (Altcoin Roundup: High Ethereum fees kick-start a liquidity migration to layer-1 platforms).

Product

A number of bridges, bridging technologies and bridging networks are available across various blockchains and these vary in maturity, security, transparency, performance and user experience.

In general, the user experience in many bridging solutions is poor, and users often find themselves in limbo for hours or even days wondering whether their assets have simply been lost or whether the transaction will be completed and the assets will appear on the destination chain.

Applied Blockchain's "London Bridge" will focus on security, cost and user experience.

Applied Blockchain proposes building a new trustless blockchain bridge framework "London Bridge", based initially on Intel SGX. The reason for starting with SGX is to ensure rapid time to market, a high level of security and "trustlessness", and in particular low-cost gas fees on Ethereum.

We propose a tactical, secure and efficient short term solution using Intel SGX, while we continue to explore and produce a long term strategic path using trustless on chain verification of the other chain, where the former is built with a view to reusing components for the latter.

Expected Benefits for Cardano

Cardano will benefit from additional liquidity provided by a safe, low cost and secure bridging solution. The many applications being developed on Cardano, some of them by the Applied Blockchain team, will be able to seamlessly integrate with other chains, providing a more active ecosystem for DeFi, NFT's and other applications.

We propose two solutions:

• London Bridge / SGX EditionThis will enable immediate rollout, with light client verifications made in the SGX environment where all functions for verifying both chains are available, This will also keep cost to a minimum, as consolidation of relayer votes and block header verifications can occur off chain. Trust is anchored in Intel's attestation of the enclave, and the code running in the enclave.
• London Bridge / Trustless EditionThis will be a more long term solution where light client verifications are made fully on chain, requiring only relayers to transmit block headers and transactions. This is a more "trustless" architecture.

We will also follow a path to decentralisation testing initially with a centrally hosted implementation, and then gradually relinquishing control to other operators.

Acquisition:

London Bridge is already being integrated with a number of other blockchains (initially Ethereum and Algorand), and will be extended for Cardano. The team will work with fungible and non-fungible token originators to support their tokens through the bridge, and ensure that wrapped assets can be easily verified on-chain.

IP

The platform will be open source.

Cost Breakdown

1. Extend London Bridge trustless token bridge to verify Cardano state and enable fungible and non-fungible token locking. $25,000
2. Extend London Bridge trustless token bridge to enable Cardano to verify Ethereum state and enable fungible and non-fungible token minting. $25,000

Roadmap

1. Extend London Bridge trustless token bridge to verify Cardano state and enable fungible and non-fungible token locking. End of Month 2.
2. Extend London Bridge trustless token bridge to enable Cardano to verify Ethereum state and enable fungible and non-fungible token minting. End of Month 3.
3. Extend SGX bridge code to support Cardano state verification. End of Month 4.
4. Integration with Cardano and Ethereum testnets.
5. Integration with Cardano and Etheruem mainnets.

Defining success

Success will be defined as:

Successful technical integration and deployment of London Bridge trustless token bridge with the Cardano testnet and mainnet.

Successful transfer of tangible and non-fungible tokens on Ethereum and Cardano through London Bridge.

Successful onboarding of Ethereum and Cardano token originators to support transfer through London Bridge.

Great success will mean achieving 4 in large numbers.

Super success will mean the bridging a significant portion of Ethereum assets and liquidity to Cardano (and vice versa).