MAP Protocol: The Pioneer of Active Relay Chain Cross-chain Interoperability

2023.03.17

MAP Protocol: The Pioneer of Active Relay Chain Cross-chain Interoperability

Layer 1 can process and finalize transactions on its own blockchain and comes with a native token used to pay for transaction fees. Ethereum is a giant in this space, but it cannot dominate the market alone. Due to technological, ecological, and competitive reasons, each mainchain operates like an isolated island, unable to interconnect or transfer assets between one another.

2023.03.17 - 08:20:26

区块链Layer1

Navigating Web3 tides with focused insights

Project Background

1. Layer 1 and Closed Silos

Layer 1 refers to the underlying blockchain networks
Examples include Ethereum, Bitcoin, Solana, Polkadot, Near, Cosmos, Aptos, Sui, etc.
They serve as the primary networks within their respective ecosystems
Layer 1 blockchains can process and finalize transactions independently on their own chains, and have native tokens for paying transaction fees
Ethereum dominates, but cannot monopolize the market

MAP Protocol: Pioneer of Active Relay Chains

https://defillama.com/chains

L1 ecosystems are thriving and continuously eroding Ethereum's ecosystem share

Due to technological, ecological, and competitive reasons, each mainchain operates like an isolated island, unable to interconnect or transfer assets between them

2. Cross-Chain Technology

Cross-chain technology enables interoperability among multiple chains, primarily involving token exchange, token transfer, and information transmission
The current siloed state of blockchains limits diversified user demands and blockchain scalability
With the continuous growth of new dApps, there is an increasing need for asset transfers and data interoperability
Cross-chain technology is considered the "holy grail" of the blockchain field and a key enabler for universal chain connectivity
Its importance can be compared to TCP/IP in the internet era—just as TCP/IP connected networks into the Internet, cross-chain connects blockchains into Web3
Huge demand from Web3

1. The total TPS required by Web3 could reach tens of billions, which even numerous L1s together may fail to support

2. There is a strong demand to aggregate all L1s into one unified system

3. Cross-Chain Paradigms

1. Hash Time-Locked Atomic Swaps

Basic principle

User A generates a random secret r, computes its hash m = hash(r), and sends m to User B;

Meanwhile, User A initiates a transaction to send 1 BTC to User B, conditional upon User B revealing r; otherwise, the transaction automatically fails after a preset time;

Upon seeing User A’s transaction, User B also initiates a transaction to send 10 ETH to User A, conditioned on User A revealing r;

After observing B's transaction, User A reveals r, allowing B’s transaction to succeed and receive the 10 ETH, thereby disclosing r;

User B then uses the revealed r to unlock A’s transaction, receiving the 1 BTC;

If the timeout (hash time lock) expires, both transactions fail;

The hash value and time lock enable trustless atomic swaps between two parties without any intermediary or trust assumptions—since hash functions are irreversible, knowing m does not allow derivation of r
The transactions are coupled into a single event: either both succeed or both fail, preventing scenarios where A pays B successfully while B fails to pay A
Both parties must be online simultaneously and strictly follow the process—if no counterparty is available, users must wait
Relatively high transaction fees
Cannot support token transfers or broader cross-chain information messaging
Often used in combination with other cross-chain technologies

2. Multi-Party Validators (Witnesses)

Validators may be permissioned or open-access
User trust in validators may stem from their reputation or over-collateralization
Validators can be designated, rotated, or randomly selected
This model is relatively easy to implement, highly versatile, and low-cost to adapt
If hackers breach validator servers, they can steal all locked cross-chain funds
Project operators could misappropriate funds
The entire validation process cannot fully eliminate malicious behavior risks
In 2022, cross-chain bridges suffered $2 billion in theft losses, with MPC-based projects being hit hardest
Mainstream cross-chain solutions such as Multichain, Celer, and Axelar adopt MPC

3. Centralized Oracle Models

Oracles and relayers operate independently and verify each other
Chainlink’s oracle submits source chain cross-chain information (receipts) to the destination chain, while the relayer also submits cross-chain data (blockhash and blockreceiptsRoot). The destination chain’s verification contract checks the consistency between the receipt submitted by the relayer and the receiptsRoot submitted by the oracle (note: order mismatch needs confirmation). If verified, the receipt is deemed legitimate and forwarded to upper-layer protocols, triggering subsequent cross-chain operations
It must be assumed that relayers and oracles act independently—an assumption that cannot hold indefinitely, making collusion fundamentally unpreventable
Relayers are ranked by staking amount and randomly chosen, but still represent centralized authorities, leaving risk of collusion between oracles and authoritative figures
Oracle data feeds lack precision and sufficient decentralization to provide cryptographic proofs, enabling potential collusion among third parties
An example project using this model is LayerZero
Not fully decentralized

4. Light Clients

4.1 What Are Light Clients?

Also known as light clients
A lightweight node that stores only block header information
Does not store all transactions on the chain, but can verify message authenticity from the source chain via block headers
The general process is as follows:

When Chain A (e.g., SOL) requests to transmit a cross-chain transaction to Chain B (e.g., ETH), the sender submits the transaction details, block height, and SPV proof (Merkle path of the transaction) to Chain B;

The light client contract of Chain A deployed on Chain B recalculates the block header hash using the SPV proof;

This computed hash is compared with the corresponding block header hash stored in the light client; if they match, the transaction is confirmed to exist in that block; otherwise, it is invalid;

4.2 Two-Way Pegged Dual Light Clients

Both chains are independent mainnets with consensus mechanisms and native tokens, each providing security guarantees
The relationship between source and destination chains is relative—either chain can act as the source in different messages
In a cross-chain message event, the originating chain is called the source chain, and the receiving chain is the target chain
By embedding each other’s light clients, two chains can read each other’s data and achieve mutual connectivity—a structure known as two-way pegging
Relayer groups exist in both directions to relay information
Representative project: MAP Protocol, which establishes two-way pegging with every connected chain

4.3 Subnet Two-Way Pegging

Subnets communicate with parent chains via light clients, as seen in Polkadot and its parachains, Cosmos and its zones, or Aurora and its subnets
Subnets lack independent consensus and native tokens—their security relies entirely on the parent chain, creating unidirectional dependency. Sidechains, however, are independently operated blockchains whose relationship with the mainchain is bidirectional

4.4 Relay Chain Architecture

Establishing direct two-way pegged light clients between every pair of chains leads to exponential growth in connections and integration costs as the number of chains increases
Solution: Build a dedicated relay chain containing light clients for all other mainchains. Then deploy the relay chain’s light client on each individual chain. This reduces connection complexity from n(n−1)/2 to just n (where n is the number of chains)

4.5 Advantages of Relay Chain-Based Light Clients

Shared Mainnet Security

The relay solution is a variant of two-way pegging, sharing mainchain security;

Transaction verification through block headers is cryptographically guaranteed—transaction validity does not depend on validators, ensuring full decentralization;

The verification logic of the light client matches that of the source network, inheriting its security;

Relayers cannot forge block headers because the light client contract can rigorously validate blocks like a full node—fake headers will fail verification;

If malicious relayers collude, the only feasible attack is submitting headers from a forked chain—but in a healthy network, forks won’t become the longest chain;

Only if the source or destination chain itself undergoes reorganization would the light client contract be compromised;

Fully Decentralized

Unlike validators, relayers are governed by smart contracts, eliminating centralization;

No reliance on privileged or authorized third parties for legitimacy verification;

Lower Operational Costs, Broader Decentralization Future

Relayers in light-client sidechains do not require over-collateralization like witnesses, enabling cheaper issuance of cross-chain anchored assets;

Light clients do not require powerful hardware or high bandwidth like full nodes—can run on smartphones or embedded devices, promoting greater decentralization;

Enables lightweight verification of transaction validity across ledgers
Uses mutually embedded light client contracts for independent self-verification
Highly scalable and currently the most widely adopted cross-chain approach

4.6 Disadvantages of Relay Chains

Different integration schemes must be developed based on the characteristics of each connected chain, requiring active compatibility efforts and significant workload
Varying levels of security across chains introduce cross-chain credit risk management challenges to protect the overall network
As new blockchains emerge with novel features, new adaptation modules must be developed accordingly

4.7 Vision for Full-Chain Connectivity via Relay Chains

Full-chain connectivity represents the future of multi-chain systems—an ultimate solution to cross-chain problems
Truly achieving universal interconnection among all chains
A single relay chain could become layer0 in the blockchain world, with other chains connecting as layer1, layer2, etc.
The relay chain is more than just a bridge—it acts as a central hub ("chain hub") responsible not only for message passing but also for inter-chain routing and message sequencing
dApps, protocols, and users across different mainchains interact seamlessly and transparently, greatly enhancing user experience
Connects users and assets across all blockchains, ending ledger fragmentation
Represents the optimal growth strategy for dApps in a multi-chain landscape and a key driver for Web3 expansion
In an increasingly competitive multi-chain future, full-chain infrastructure may prove even more critical than L2 scaling solutions

4.8 Dominant Relay Chains: Polkadot and Cosmos

Polkadot’s parachains and Cosmos’ Hub exemplify “two-way pegging” relationships, embodying relay concepts aimed at universal connectivity
Cosmos’ Inter-Blockchain Communication (IBC) protocol verifies cross-chain messages via light client contracts built into recipient chains. In contrast, Polkadot’s XCMP does not use light clients but relies on shared validators
Neither Polkadot’s relay chain nor Cosmos Hub is Turing-complete and cannot execute smart contracts natively. Polkadot introduced Substrate, while Cosmos created the Cosmos SDK. These cross-chain SDKs require integration at the base layer of other chains. For established blockchains like Ethereum, BNB, Klaytn, Polygon, and Avalanche built without these tools, deep structural modifications are needed to achieve compatibility—posing extremely complex technical challenges. As a result, no thriving L1 has yet achieved interoperability with Polkadot or Cosmos Hub
To connect with Polkadot’s relay chain, a chain must surrender its accounting authority—and thus its security—to the relay chain, which prosperous L1 ecosystems cannot accept
For dApp developers, using Polkadot or Cosmos requires first launching their own L1 before deploying applications. However, building an L1 is not a core requirement—reaching more users and assets is. From development cost, learning curve, and security perspectives, this path is inefficient and uneconomical
Although Polkadot and Cosmos employ secure light client mechanisms, they function more like closed internal ecosystems. Their actual performance in enabling true interconnectivity and expanding dApp reach remains suboptimal. Their architectural designs make it difficult to interoperate with major chains like Ethereum and BNB. While they offer convenient chain-launching tools, they fail to address dApps' fundamental need for broad user and asset coverage
Any mainchain wishing to link with Polkadot or Cosmos must proactively adapt
To date, there has been no sign of motivation or movement toward mutual compatibility

MAP Protocol Project Analysis

1. Project Overview

MAP Protocol’s mainchain (Relay Chain) serves as a relay chain hosting light clients for all other major chains
MAP Protocol has already installed its own light client on its mainchain
MAP Protocol proactively pre-compiles signature algorithms and hash functions of various thriving L1s into its relay chain’s contract layer
It comprehensively connects mainstream EVM and non-EVM chains such as Ethereum, Polygon, BNB Smart Chain, Klaytn, and NEAR. It deploys MAP Protocol’s light client as a smart contract on each of these L1s
Through light clients and existing relay chain light clients on mainchains, all L1s become isomorphic with the relay chain, achieving cross-light-client validity verification

2. Project Architecture

1. Protocol Layer – Core Foundation

Composed of the MAP Relay Chain, light clients deployed across chains, and the inter-chain message maintainer program (Maintainer)
The MAP Relay Chain’s virtual machine layer incorporates major L1 signature algorithms, hash functions, and Merkle Tree proofs via precompiled contracts, turning the relay chain into a “super-language machine” fluent in multiple blockchain protocols. This enables seamless communication between chains and lays a foundation for isomorphic interoperability

Light clients feature independent self-validation and instant finality. Based on the isomorphic foundation of the MAP Relay Chain, the cross-validating light client network shares a common data language, enabling easy deployment as smart contracts on any compatible L1 for decentralized cross-chain validation

Maintainer is an independent inter-chain message program responsible for updating the latest state of light clients. It writes consensus-layer block headers (validator signatures) from various chains into the corresponding origin-chain light client contracts on target chains, ensuring alignment between the light client and the origin chain’s validator set

2. MOS – Omnichain Service Layer

MAP Omnichain as a Service Layer
Analogous to Google Mobile Services for Android, providing full-chain development services for dApp developers
This layer includes cross-chain asset locking smart contracts and the Messenger inter-chain messaging component deployed across blockchains. Developers can directly leverage this layer to build omnichain applications or further customize components, significantly reducing development and learning costs
All smart contracts in this layer are open-source and audited by CertiK, so developers can use them safely without worrying about security or cost

3. Omnichain Application Layer

Omnichain Application Layer
Take decentralized derivatives and synthetic assets as examples—they are currently constrained by inaccurate or delayed price and quantity data from other chains. Off-chain oracles cannot deliver precise, timely information, resulting in poor liquidity and user experience
While multi-chain deployment can mitigate this issue, it is time-consuming, labor-intensive, and adds unnecessary development overhead
By deploying on the MAP Relay Chain, decentralized derivatives and synthetics can access accurate multi-chain data via MAP Protocol’s on-chain oracle, overcoming data flow barriers and enabling smooth cross-chain asset movement
Other potential use cases include omnichain DID, omnichain lending, omnichain swap, omnichain GameFi, omnichain DAO governance, omnichain tokens, and omnichain NFTs. Regardless of where a dApp’s core contract resides, developers can easily build applications capable of reaching users and assets across all chains using MAP Protocol

4. zk Technology Integration

Signature Verification: Merkle proofs for specific Merkle roots, hash linking, and cumulative work checks are suitable for authentication via zkSNARKs
In light client construction, zk techniques simplify storage of large validator group info or block headers
Commitments represent validator sets (PoS) or latest block headers (PoW), updated whenever the set changes
zkSNARKs prove that transitions from old to new commitments reflect valid changes in validator or block header sets
Constraints enforced by zkSNARKs mainly involve checking whether enough previous validators approved the new set and whether voting weight meets a threshold

3. Full-Chain Use Case Examples

1. Cross-Chain Lending

Currently, if a user holds funds on Chain A but wants to stake on Chain B, they must go through nine steps:

Pledge on Chain A → Borrow → Bridge (fee) → Swap (fee) → Stake on destination chain → Swap back (fee) → Bridge back (fee) → Repay loan → Unstake;

With MAP Protocol: Pledge on Chain A, borrow, stake, repay, and unstake directly on the destination chain—skipping four bridge and swap fees

2. Omnichain Swap

Omnichain Swap connects top-tier cross-chain DeFi protocols, enabling token exchanges at far lower fees than traditional DEXs
Developers can build a truly decentralized omnichain exchange using MAP Protocol, allowing users to swap any token on any chain
Omnichain Swap can aggregate liquidity from major DEXs for unified cross-chain swapping
Existing AMMs can be wrapped to enable full-chain asset swaps without modifying underlying code
Users can swap ETH on Ethereum to NEAR on NEAR in a single transaction from the source chain
In MAP-based omnichain swaps, users can add multi-chain tokens to a single pool, enabling liquidity provision across token pairs from different chains
Users can directly swap tokens across different chains without intermediate stablecoins, achieving the shortest possible conversion path
Butter Swap is the first truly decentralized cross-chain network enabling swaps between any tokens on any chains. It is currently in testing and soon to launch

3. Omnichain GameFi

With MAP Protocol, GameFi projects can deploy tokens across multiple chains and allow users from other chains to securely and efficiently transfer assets to their game chain
For example, a BNB Chain GameFi project deploying tokens on Polygon and WAX allows users from BSC and Polygon to bridge assets to WAX and participate, multiplying user base
Another scalable approach with good gameplay experience is direct deployment on the MAPO Relay Chain. Thanks to MAPO’s interoperability, GameFi projects automatically connect securely and efficiently with all EVM and non-EVM chains. The MAPO Relay Chain actively integrates upcoming chains, allowing GameFi teams to focus on UX rather than scalability or security concerns

4. On-Chain Data: On-Chain Oracles and Derivatives

MAP Protocol enables data cross-chain and is fostering a new oracle market—the on-chain oracle
By deploying on the MAPO Relay Chain, derivative and synthetic asset applications can easily obtain reliable multi-chain data from on-chain oracles

5. Omnichain Governance

Take Aave as an example
As stated by its developers, a proposal executed on Ethereum (ETH) is sent to Polygon FxPortal. The mechanism reads Ethereum data and forwards it to Polygon for validation. Then, Aave’s cross-chain governance bridge contract receives and decodes the data, queues the action, and waits for timelock completion. Aave’s cross-chain governance bridge is built generically and can easily adapt to operations with any EVM-compatible chain supporting cross-chain messaging
Currently, the repository supports contract bridging with Polygon and Arbitrum. On Aave, users can submit Aave Improvement Proposals (AIPs) targeting various platform functionalities. With MAP Protocol’s universal chain interoperability, secure cross-chain infrastructure enables full-chain governance across all EVM and heterogeneous chains

6. Fungible Token and NFT Bridges

Cross-chain bridges and NFT bridges no longer need to build their own infrastructure or rely on MPC
Using MAPO’s underlying cross-chain verification network with instant finality and the MOS developer service suite, bridge developers can easily build NFT or fungible token bridging applications

4. Project Advantages

1. Full-Chain Interoperability and Universal Cross-Chain Support

Unlike Cosmos, Polkadot, or Aurora, MAP Relay Chain achieves isomorphism with all chains, connecting all L1s—not just those within its ecosystem. It is the only full-chain infrastructure in the market offering complete chain coverage and the highest level of security
Through the relay chain, fragmented public ledger systems become a unified distributed ledger
NEAR’s Rainbow Bridge, Polkadot, Cosmos IBC, and MAP Protocol all use 100% Nakamoto consensus and mathematically provable light-client self-verification. However, Polkadot, Cosmos IBC, and NEAR’s Rainbow Bridge cannot support all chains—only their own ecosystems. For instance, Polkadot and Cosmos IBC cannot facilitate cross-chain interactions with heterogeneous chains like Ethereum, BNB Chain, or Polygon. Rainbow Bridge currently only supports Aurora (NEAR’s EVM)

2. Fully Decentralized, No Privileged Roles, 100% Nakamoto Consensus

The triad of light clients, Maintainer, and Messenger mutually verify each other, ensuring authenticity and security throughout the cross-chain validation process. The design inherently prevents malicious behavior by Messenger and Maintainer. This is a blockchain-level cross-chain verification mechanism under 100% Nakamoto consensus—fully provably decentralized, relying neither on off-chain data nor on privileged third-party roles
LayerZero includes light clients, but only for intra-chain verification, not cross-chain validation, and involves ambiguous privileged roles (oracles)

3. Shared Mainchain Security

MAP Relay Chain adopts a relay model via two-way light client anchoring. The verification logic of the light client exactly mirrors that of the source network. This dual-mainnet verification mechanism is cryptographically secured—only malicious fork attempts could compromise the light client contract, making it the most secure cross-chain solution available today

4. Compatible with Both EVM and Non-EVM Chains

The relay chain pre-integrates signature and hash algorithms of various public chains, enabling not only multi-chain expansion but also seamless linking between EVM and non-EVM chains, supporting secure and frictionless cross-chain communication and asset transfer

5. Developer-Friendly Design

Compatible with nearly all blockchains and supports native dApp deployment on the relay chain
Provides a light-client-based cross-chain SDK that allows direct integration at the base layer of any blockchain
Offers proprietary SDKs that reduce dApp development complexity
Features a unique zero-knowledge-proof-based light client design that lowers development difficulty for heterogeneous chains while ensuring cross-chain message security

6. Lower Operating Costs, Broader Decentralization Outlook

Relayers in light-client sidechains do not require over-collateralization like validators, enabling more efficient issuance of cross-chain anchored assets at lower cost
Optimizes data verification costs via ZK + light client cross-chain validation, reducing gas fees

5. Team

MAP Protocol was founded in 2019
It is a team entirely driven by a culture of hacker engineers and researchers

6. Social Engagement and Promotion

Twitter followers: 106,000

High tweet engagement

Founders actively participate in various events

Proactive collaboration with other projects

7. Tokenomics

Total supply: 10 billion

15% allocated to team incentives
21% allocated to Ecosystem DAO
12% held by MAP Protocol Foundation
22% for investors and early supporters
30% reserved for mining rewards

8. Market Valuation

Market Cap: $22,342,490
Circulating Supply: 2,228,621,190
Circulation Rate: 22.3%
Fully Diluted Valuation: $101,348,762

9. Holder Distribution

10. Code Development Status

Code development began in 2021 and has continued uninterrupted, with frequent updates

10 contributors involved in code development

Eight version iterations completed

11. Expert Evaluations

1. Bohao Tang, Chief Developer at Flow

MAP Protocol is helping Flow build infrastructure for a full-chain application experience. Its cross-chain verification eliminates privileged roles and supports all EVM and non-EVM chains. We believe it can bring richer possibilities to the Flow ecosystem

2. Professor Yang Liu, Director of Cybersecurity Lab at Nanyang Technological University

MAP Protocol’s full-chain interoperability offers superior security, compatibility, and developer-friendliness compared to other cross-chain solutions. “MAP Protocol’s mature, innovative, and stable cross-chain design enables secure and seamless communication and asset transfer between EVM and non-EVM chains. Compared to centralized, no-relay-chain solutions like Axelar and Celer, MAP Protocol’s relay chain not only simplifies multi-chain architecture scalability but also avoids risks associated with super-administrators controlling inter-chain communications.”
“Compared to decentralized relay-chain solutions like Polkadot and Cosmos, MAP Protocol uniquely integrates zero-knowledge proofs, using smart-contract-based light clients to verify inter-chain messages. This lightweight implementation eliminates the need for SDK embedding or structural compatibility at the base layer of heterogeneous chains, while guaranteeing message security and confidentiality—enabling interoperability with virtually all blockchains.”
“Most importantly, MAP Protocol’s innovative design allows dApps to develop and natively deploy directly on the relay chain. By integrating assets from various blockchains, MAP Relay Chain becomes a pivotal component for cross-chain asset and data interaction—and stands a strong chance of becoming the true future of cross-chain solutions.”

12. Conclusion

A high-quality solution for cross-chain connectivity (shared mainchain security, decentralized)
Universal cross-chain and full-chain interoperability with vast potential
Team with years of deep technical accumulation
High-quality project, yet currently undervalued

References:

https://files.mapprotocol.io/pdf/mapprotocol_Litebook_cn.pdf

https://www.panewslab.com/zh/articledetails/D62579631.html

https://foresightnews.pro/article/h5Detail/19308
https://view.inews.qq.com/k/20230206A02IC400?web_channel=wap&openApp=false

Join TechFlow official community to stay tuned

Telegram:https://t.me/TechFlowDaily

X (Twitter):https://x.com/TechFlowPost

X (Twitter) EN:https://x.com/BlockFlow_News

Add to Favorites

Share to Social Media

AuthorAvatarDAO