Blockchain bridges have become an essential tool for moving crypto assets across different blockchains. These protocols facilitate the interoperability between different Web3 networks and enable users to benefit from the unique features and opportunities offered by each of them. This article will explore several of the most popular crypto bridges – Multichain, Portal Token Bridge, AllBridge, ChainPort and Orbit Bridge. We will delve into the features, advantages and security mechanisms to see what makes each of them a competitive and sought after protocol.
Multichain, formerly known as Anyswap, is one of the most popular open-source cross-chain protocols out there. Multichain seeks to be the ultimate Web3 router providing the user with the ability to transfer assets between as many chains as possible. Currently, Multichain is the bridge with the most tokens and chains available with more than 3000 tokens and 80 plus chains.
One of the bridge’s standout features is that depending on the asset being bridged it can choose the best method for transferring the user’s assets. The protocol supports two different ways of doing that – through the locking-and-minting mechanism or with the utilization of liquidity pools. If the token being bridged has a native implementation on the target network then liquidity pools can be used without slippage. If there is no native token then the tokens will be locked in a smart contract and a wrapped version of the tokens will be created on the target network. This is all thanks to Multichain’s Router.
Another feature with which Multichain stands out is anyCall. The protocol is a versatile cross-chain messaging router that facilitates communication between Dapps across different chains via cross-chain messages and contract calls from one chain to another. It simplifies the process of invoking contracts native to a particular blockchain from any other blockchain, with Multichain nodes providing security for the calls. AnyCall, using a single transaction, allows for the transmission of data, such as smart contracts, NFTs, messages, tokens, and other data, to any blockchain.
Potential use cases for the protocol are cross-chain swap, cross-chain NFT, cross-chain lending, cross-chain arbitrage bots, cross-chain oracles and unified metaverses. A real example would be the partnership with Curve Finance where anyCall helps Curve build a unified CRV rewards mechanism by allowing them to create gauges on other chains.
As far as security is concerned, Multichain is maintained by a network of nodes referred to as Secure Multi-Party Computation (SMPC). These nodes act as independent entities that collectively sign transactions through a process enabled by the Distributed Key Generation algorithm. Each node possesses a portion of the private key that is never completely revealed, eliminating the possibility of single points of failure and ensuring the system’s decentralization and security. The SMPC nodes are run by different organizations, institutions and individuals and they are incentivized to perform their functions properly.
On top of that, the protocol’s smart contracts have been audited by SlowMist, PeckShield, BlockSec, CertiK, Trail of Bits, Verichains and Dedaub. Also, they have their self-hosted Bug Bounty Program (BBP) where independent security researchers are incentivized to identify and report vulnerabilities.
Multichain’s MULTI token is the governance that allows the token holders to participate in the governance of the community and the ecosystem. After the rebranding of the bridge from Anyswap to Multichain, the old token ANY is interchangeable with the new one MULTI in a 1:1 ratio.
Last but not least, Multichain is one of the few interoperability solutions that offers a bridge for NFTs, both ERC721 and ERC1155.
Portal Token Bridge
Portal Token Bridge, is a cross-chain protocol that supports more than 20 networks including BNB Smart Chain, Polygon, Optimism and Arbitrum. Portal was initially built to connect Solana and Ethereum and was known as the Wormhole bridge. Since then the bridge has been rebranded to Portal Token Bridge and the Wormhole moniker now refers to the underlying protocol that powers the bridge .
The bridge utilizes the locking-and-minting mechanism and it is secured by a network of 19 nodes called guardians. These guardians are typically large-scale institutional staking service providers such as Everstake and Jump Crypto which have been actively involved in Solana staking and are trusted by the platform. Each of them has an equal weight when it comes to approving transfers. Also, in order for a transfer to be successful at least two-thirds of the guardians have to verify and approve it.
The bridge has been audited by trusted security firms such as Neodyme AG, Kudelski, OtterSec, Trail of Bits, Hacken Coinspect, Halborn and CertiK. In addition, the underlying protocol Wormhole has a bug bounty program hosted on Immunefi.
One of the advantages of the Portal Token Bridge is that it offers really low fees – just $0.0001 per transfer. Another is that Portal is one of the few bridges that support Solana as a network so that users can benefit from the Solana ecosystem and also open the doors to other networks for the current Solana users.
Furthermore, the protocol offers NFT(only ERC721) bridging. And while we are not the topic of the NFTs, Portal has a pretty interesting feature called NFT Origin Verifier. The tool provides the user with information about a given NFT which helps the user verify the authenticity of the NFT.
Allbridge is a fast, affordable and secure way of moving crypto assets between different blockchains. The bridge supports more than 20 networks including EVM and non-EVM ones. In the near future, the protocol is expected to implement L2 networks such as Optimism and Arbitrum and make NFT transfer available. The platform offers three main products – Allbridge Classic, Allbridge Core and Allbridge BaaS. We are going to have a closer look at each of them below.
Just like Multichain, Allbridge uses the mint-and-lock mechanism and for some stablecoins, it utilizes liquidity pools on the different networks. Тhe former is under the Allbridge Classic product line and the latter is Allbridge Core which enables users to bridge(swap) USDT, USDC and BUSD across Ethereum, Binance Smart Chain, Tron and Solana.
One of the most interesting and unique products of the bridge is named Allbridge BaaS (Bridge as a Service). It is a white-label bridging solution with a simple customizable UI, it offers a flexible architecture set up and it provides full ownership of smart contracts and a validator. The product has a number of advantages compared to a 3rd party or a custom-made bridge – a wide range of supported networks, fast integration and development and low fees.
The protocol has its own token – ABR. The token holders can stake their ABR via the bridge to get reduced bridging fees and earn staking rewards. Stakers can also participate in Staking DAO and vote on various topics such as the reward distribution across the different chains. Also, the ABR token is used to pay bridging fees and subscription fees when a project wants to use the bridge on a monthly basis.
Moreover, Allbridge has been audited by Hacken, Kudelsky and Cossack Labs. Also, it has a bug bounty available on HackenProof.
ChainPort is a permissionless bridge with a security-focused architecture that enables porting 100 different assets between more than 10 networks – from EVM-compatible ones such as BNB Chain and Polygon to Cardano to L2 networks such as Arbitrum and Optimism. As per its roadmap, the bridge is set to expand its offering by adding new features such as NFT porting and doubling its supported networks to more than 20 by the end of 2023.
The protocol puts its security as utmost priority, boasting battle-tested and robust security features. These features include funds segregation, multi-sig and MPC cold wallets, and multiple independent security audits. Fund segregation is at the core of the security architecture of the bridge. Instead of the user’s funds being stored in a single wallet or a contract, they are kept in different cold storage vaults. Forty five percent f of the funds are secured by Fireblocks MPC Multi-sig which qualifies the bridge as one of the most secure ones. Half of all funds are kept in Cold Storage Multi-Sig Safe hosted by Gnosis and are kept in different vaults and locations to reduce the number of potential attack vectors. Both of the cold wallet solutions limit transfer of funds to a pre-set address and any change needs to be signed and verified by the multi-sig congress. The remaining 5% are kept in hot storage in ChainPort’s smart contracts. These are the most exposed funds to attacks. To mitigate any potential risk, the bridge has a freeze mechanism designed to pre-empt attempts to misappropriate funds. Any unusual interaction pattern leads to an immediate freeze of the bridge and triggers an alert to ChainPort’s SOC (Security Operation Centre). During a bridge freeze, no funds can be transferred in or out of the wallet.
The bridge has been audited by security firms such as CertiK and CyberUnit. In addition, CertiK’s Skynet continuously monitors the protocol’s smart contracts through static and dynamic scans. Currently, ChainPort does not have a bug bounty program but it plans to launch a self-hosted one soon.
PROTX Token is the native utility token of the platform. It is mainly used to pay for bridging fees at a discounted rate compared to other tokens not associated with the platform and also it is used for staking and claiming rewards.
Last but least, ChainPort offers a private bridge for businesses that look for customized bridging solutions.
Orbit Bridge is an interchain communication protocol that allows communication between heterogeneous blockchains. Through this, users can utilize the various assets of various chains in all dApps through simple transactions on each chain. It supports more than 20 networks and almost 100 tokens. Using the protocol users are able to bridge NFTs as well.
Each transaction of the bridge is signed by a validator and to be executed it has to reach a certain threshold of signatures. Compared to MPC where there is a single shared key between each node in the validator swarm, each of Orbit Bridge’s validators have their own private key that is used to sign the transactions. The protocol has different groups of validators available and the users are also able to choose which group of validators to use to secure and validate their transactions.
ORC is the utility token of the platform and is a means of participating in Orbit Chain governance & PoS-based block generation and a backbone in the maintenance and expansion of the Orbit Bridge.
The bridge has been audited thoroughly by Theori and currently, it has no bug bounty program available.