Previously Anyswap, Multichain is a platform that facilitates the bridging of cryptocurrencies and NFTs between different blockchains. Multichain enables users to bridge assets either through pegged tokens or liquidity pools. In 2021, the platform raised a $60 million financing round at a $1.2 billion valuation led by Binance Labs. ^[1][2]

History

Founded in July 2020, Anyswap was initially positioned as a cross-chain DEX. In early 2021, the DEX function was removed by Anyswap, and the focus shifted to cross-chain bridge services. ^[3]

Hacking

On July 7, 2023, Multichain announced through Twitter that their services had stopped and all bridge transactions would be stuck on the source chains, and asked users to not use Multichain bridging services, after detecting an unusual movement of a large quantity of tokens from its bridging networks to an undisclosed address. ^[4]

Just hours prior, Multichain was alerted by PeckShield, a blockchain security firm, regarding suspicious activity observed on its Fantom (FTM) bridge. The activity indicated significant outflows of tokens, amounting to approximately $102 million. Tokens such as wrapped Bitcoin (WBTC), USDC, DAI, ether (ETH), and chainlink (LINK) were among those affected by the suspected exploit. The estimated losses resulting from these transactions surpassed $130 million. ^[4]

Missing CEO

On May 21, 2023, Multichain CEO Zhaojun was taken by the Chinese police from his home and has remained uncontactable by the global Multichain team since then. The team discovered that their operational access keys to the MPC node servers had been revoked. These MPC node servers, including all other ordinary servers, were running under Zhaojun's personal cloud server account. As a result, no team member has access to Zhaojun's personal cloud server account, preventing them from logging onto the MPC servers. ^[11]

Subsequently, the team established communication with Zhaojun's family and learned that the authorities had confiscated Zhaojun's computers, phones, hardware wallets, and mnemonic phrases. Since the project's inception, Zhaojun had maintained control over all operational funds and investor investments. Consequently, both the team's funds and access to the servers are now under the control of Zhaojun and the police. ^[11]

Due to the limited information available about the case, the team has been managing project operations to the best of their abilities using the remaining access they have to non-MPC servers that have not been revoked. In line with their lawyer's advice, the team has chosen to cooperate as much as possible with the demands of Zhaojun's family and comply with local laws and regulations. They have refrained from disclosing unauthorized information about the case to the public. ^[11]

On May 30, the team responsibly announced Zhaojun's disappearance to the community and informed them about the ongoing technical issues they were facing. ^[11]

On June 4, Zhaojun's family successfully logged into the cloud server platform using historical information from Zhaojun's home computer. However, they only allowed Multichain team engineers physical access to the home computer to address technical issues with Router2 and Router5. ^[11]

During this period, Zhaojun's family and their lawyer remained in communication with the police. Although the team was not informed about the case's details, they were notified that Zhaojun would be released soon and were requested to continue maintaining the system while awaiting further updates. ^[11]

Despite the challenging circumstances, the Multichain protocol has continued to operate as designed. The team has made every effort, given their limited resources, to sustain the protocol's operation and address user issues to the best of their ability. ^[11]

On July 7, there was an abnormal transfer of user assets locked on the MPC addresses to unknown addresses. According to Zhaojun's sister, login information from an IP address in Kunming was discovered on the cloud server platform, along with a series of operations involving the transfer of funds from the MPC addresses. ^[11]

Subsequently, on July 9, Zhaojun's sister took action to transfer the remaining user assets in the router pool. The team was notified of this asset preservation action, and the funds were transferred to Ethereum EOA addresses controlled by Zhaojun's sister, identified as 0x1eed63efba5f81d95bfe37d82c8e736b974f477b and 0x6b6314f4f07c974600d872182dcde092c480e57b. ^[11]

On July 13, based on information provided by Zhaojun's family, the police took Zhaojun's sister into custody, and she is currently uncontactable. Consequently, the status of the assets she preserved is uncertain, prompting the team to inform the community about all the known circumstances. ^[11]

Due to the lack of alternative information sources and the absence of corresponding operational funds, the team has been compelled to cease operations. They have committed to updating the community if there are any further notifications and developments. ^[11]

Overview

Multichain is an open-source cross-chain router protocol (CRP) designed to facilitate token bridging across various blockchains. With support for over 74 chains, including BNB Smart Chain, Fantom, and Harmony, Multichain enables users to transfer assets between blockchains using its Cross-Chain Bridges and Cross-Chain Routers. Additionally, Multichain offers a governance token called MULTI, which allows holders to actively participate in the project's forthcoming governance mechanism. ^[5]

Cross-Chain Bridges

Bridging with Multichain involves the utilization of a standard crypto pegging mechanism for certain coins and tokens when transferring assets across different chains. Let's take the example of bridging BNB from BNB Smart Chain to Ethereum. In this scenario, Multichain employs a process where your BNB is securely locked within a smart contract on the BNB Smart Chain. Subsequently, Multichain mints a corresponding pegged BNB token on the Ethereum network. Importantly, this pegging process ensures a 1:1 ratio, meaning that each locked BNB on the BNB Smart Chain corresponds to one pegged BNB token on Ethereum. This bridging option was initially introduced by Multichain when it was operating under the name Anyswap. ^[5][6]

Cross-Chain Routers

The Cross-Chain Router functionality allows the transfer of assets across multiple chains, regardless of whether they are native to those chains or created through Multichain's Bridge. There are three categories of Routing transfer: Native Assets, Bridged Assets, and Hybrid Native/Bridged Assets. ^[7]

Native Assets

When a token already exists on a specific blockchain, it is considered a native asset, such as USDC. In the case of native assets, Multichain cannot create new tokens. Instead, Multichain employs liquidity pools as a solution. These pools consist of tokens contributed by Multichain, project teams, or individuals on each respective chain. These tokens within the pools become accessible to users when they perform cross-chain. ^[7]

Bridged Assets

When the Router utilizes assets that are created using AnyswapV5ERC20.sol or its modified version (referred to as Bridged assets), there is no need for a liquidity pool for that particular asset. This is because Multichain has control over the supply of the asset on the specific chain where the contract is deployed. In such cases, the pool size is considered 'Unlimited'. For Routed assets where AnyswapV5ERC20 entirely manages the cross-chain minting process, the only requirement is to add a supply of that asset to the pool on the chain where the token was originally minted. ^[7]

Hybrid Native/Bridged Assets

On certain occasions, it becomes necessary to combine native assets on specific chains with assets controlled by Multichain's Bridges, such as AnyswapV5ERC20.sol. This situation commonly arises when a project has already minted a supply of a token or has an existing third-party bridge for an asset on a different chain. However, after joining the Router they wish to expand and add tokens on additional chains. In such cases, the tokens existing prior to this expansion are considered 'native' to their respective chains, whereas the tokens on the newly added chains are referred to as 'Bridged' assets. ^[7]

SMPC Nodes

Multichain utilizes a network of nodes called the Secure Multi-Party Computation (SMPC) to ensure its security. These nodes operate as independent entities capable of collectively signing transactions. Through a Distributed Key Generation algorithm, each node possesses a unique portion of the private key. The complete set of private keys remains hidden, eliminating any risk of exposure. This approach effectively eliminates single points of failure, ensuring decentralization and enhancing security. ^[5]

zkRouter

zkRouter is a technological solution developed by Multichain for cross-chain bridging. It leverages zero-knowledge proofs (ZKP), specifically zk-SNARKs, to facilitate secure, efficient, and decentralized interoperability between various blockchain networks. The whitepaper was released in November 2022. ^[12][13]

Use Cases

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• cross-chain bridge: zkRouter can support different cross-chain bridge models such as Mint/Burn, capital pool, or hybrid methods.
  \
• on-chain oracle: zkRouter enables credible transfer and storage of data from one chain to another, verifying the data on-chain, while other decentralized applications can use the information relayed through zkRouter, enhancing their functionality.
  \
• cross-chain swap: zkRouter can be employed by existing decentralized exchanges (DEXs) to move into a chain-agnostic space.
  \
• multi-chain tokens and NFTs: with zkRouter, protocols can mint and issue tokens and Non-Fungible Tokens (NFTs) across various chains.^[13]

Supported Chains

EVM Chains

• Avalanche C-Chain
• Binance smart chain
• Celo
• Cronos
• Ethereum
• Fantom
• Fuse
• Fusion
• IOTEX
• Harmony shard 0
• Huobi Heco chain
• Kucoin
• Moonriver
• Moonbeam
• OKExChain
• Polygon
• Shiden
• Telos
• XDai

EVM Layer 2

• Arbitrum
• Boba

Bitcoin-like chains

• Bitcoin
• Blocknet
• ColossusXT
• Litecoin

MULTI token

MULTI serves as Multichain's governance token, succeeding the previous any governance token during the transition from Anyswap to Multichain. Through the Multichain website, users now have the ability to convert ANY to MULTI at a 1:1 ratio. This conversion mechanism ensures that MULTI will have a maximum total supply of 100 million tokens, assuming all holders choose to convert their tokens. Furthermore, Multichain introduces veMULTI, which enables token holders to stake their MULTI tokens and receive rewards in Multichain bridge fees. Additionally, veMULTI holders possess the right to participate in voting on governance proposals via the veMULTI framework. ^[5][8]

Funding

On October 14, 2020, Binance Accelerator awarded Anyswap and five other project grants worth $350,000 from its $100 million Accelerator fund. ^[9]

In 2021, Multichain raised $60 million in a financing round. This funding has resulted in a valuation of $1.2 billion for the company. The round was led by Binance Labs and saw participation from notable investors including Sequoia China, IDG Capital, Three Arrows Capital, DeFiance Capital, Circle Ventures, Tron Foundation, Hypersphere Ventures, Primitive Ventures, Magic Ventures, and HashKey. ^[10]