The grant we are applying for will be used to the development and operation of decentralized cross-chain protocol “MaraLink”, which allows anyone to send assets to applications on any blockchain. It will expand Polkadot ecosystem boundaries and bridge the gap between Polygon and Polkadot ecosystem.

Polkadot has always been a diversified paradise, continuously expanding its influence based on cooperation and mutual benefits. Amara has always upheld and advocated diversification since its establishment. We believe that we are now ready to welcome a more diverse world of Polkadot , We hope that through our own efforts, Polkadot's influence will be brought to Polygon and other ecosystems, and through diversified integration, we will build a more splendid world of Polkadot.

The number of friends who embrace our hope for fulfillment is growing, as can be seen by the number of social media subscriptions.


**Social media**

- Twitter（Amara Fiance）- over 30K followers
- Telegram subscribers exceed 40K

In order to build a more diverse Polkadot Kingdom, we developed MaraLink to help Polkadot ecosystem expand its influence.

Maralink will be a bridge between Polkadot and the outside world, introducing more assets and users into Polkadot network, and help expand the boundaries of Polkadot DeFi ecosystem. We hope that we could perfect the infrastructure of the Polkadot Ecosystem and assets outside the Polkadot chain can be effectively employed through our efforts.

MaraLink is a decentralized cross-chain assets protocol aiming at interconnecting assets between different chains and constructing an assets transfer center between Polkadot and other chains, which allows anyone to send assets to applications on any blockchain.  

MaraLink plans to implement asset transfer and mapping between Polkadot and Polygon, which is set to deploy protocols for data monitoring and matching operations on the Polkadot chain, and ultimately support Mara-Link dark node network for cross-chain operations.

**Summary of MaraLink's future plan:**

Maralink mainly consists of three parts: decentralized dark node network, protocol based on Bip-Schnorr signatures,and client node. 

- Decentralized dark node network

The decentralized dark node network is a Byzantine fault-tolerant (BFT) network consisting of hundreds of independently operating machines, and each node requires a certain amount of mortgage to operate, and the number of pledges of each node represents a commitment to good behavior , Each machine will generate a secret ECDSA private key and public key. The public key will be announced to the public. Only at least 2/3 of the dark nodes in the entire network sign and verify the transaction can be completed, which makes the entire dark node network safe and stable.

- Protocol based on bip-Schnorr signature

The protocol serves as a bridge and gateway for cross-chain assets. The results of the dark node network aggregation signature need to be submitted to the protocol for verification before the next step is successfully performed.

- Client node

The client node is the client application. The design of Mara-Link fully considers the user experience. Users do not need to know the detailed process of cross-chain(only need to interact with real assets on their real chain), which allows them to make transactions by single clicks and then build-in application data can be activated to directly run the protocol. 




Detailed design of MaraLink v0.1 (10 weeks, 10 Jul - 25 Sept. ):

**Milestone 0 : (3 developers  2 weeks)**

- Realize the construction of the dark node network environment
- Determine the consensus algorithm between nodes and the signature verification rules before the block is packaged on the chain.


**Milestone 1 : (3 developers  2 weeks)**
- Write a smart contract based on Bip-Schnorr multi-node signature verification to smoothen the process of Lock and Mint.
- Realize the consensus block generation algorithm based on Drand, realize the communication and synchronization between nodes, and store the  packaged data about transactions in the dark node network.
- Realize the verification rules as well as combined signature algorithm between the active nodes of the dark node network


**Milestone 2 : (3 developers  2 weeks)**
- Implement ranking management and status maintenance of active nodes, and add reward and punishment mechanisms.
- Realize the data interaction of Lock and Mint between the dark node network and the cross-chain smart contract.
- Implement the RPC interface required by the front end.

**Milestone 3 : (3 developers  2 weeks)**
- Integration and testing

**Milestone 4 : ( 2 weeks)**
- Release Beta and invite users on white list to participate in Beta
- Test product safety and stability and encourage users to find bugs in time
- Trace and identify the problems and fix bugs timely


**Cost of MaraLink**

Operating activities: $7000 (operation cost on launch Beta version to the public, invite professionals to test，and corresponding incentives )
Employee payments: $21000 ($700 per developer * week)

Total Cost: $28000
Exchange Rate: $11  DOT
Treasury Proposal: 2600  DOT

**How to verify : demo video && Github source**

- Realize the cross-chain of different assets in the test version
- Achieve Lock and Mint of assets by triggering the smart contract


- The grant is for a project called MaraLink, which will help connect different blockchains and allow people to send assets between them.
- The project aims to expand the Polkadot ecosystem and bridge the gap between Polygon and Polkadot.
- MaraLink has a lot of followers on social media, like Twitter and Telegram.
- The project has a plan for the future, including a decentralized dark node network and a protocol for cross-chain assets.
- They have a detailed design for the project and a plan for milestones to complete it.

#554 MaraLink Development and Operation Grant Approval Proposal