Bridging assets in crypto is not without risk. From hacks to scams to outright honest mistakes, a lot can go wrong and leave you financially wrecked (or “rekt”, as it is known in the crypto sphere).

But when done carefully and right, you can easily send your coins to your destination blockchain.

Why do you need a blockchain bridge in the first place?

Ever travelled to an exotic location for your vacation? One of the first activities you might have done on landing is to go to a local currency exchange and swap your currency for the native one.

Why? Because your currency is not a part of the local economy. You might not be able to even get your morning coffee if you don’t have the destination currency. 

In the world of cryptocurrency, the blockchains are just like different countries. With different economies, they have their own money or currency (BTC for Bitcoin, ETH for Ethereum, SOL for Solana, and so on). 

You cannot use BTC on Ethereum, nor ETH on Solana. You need a connection between two blockchains to transfer your copies between them.

What you need is a blockchain’s equivalent of a currency exchanger: a bridge.

How does a crypto bridge work

Working just like a currency exchanger, bridges allow you to convert one coin into another blockchain’s assets. All you need is your original coins, a receiving wallet on the other network, and a reputable bridge. Imagine you hold ETH on Ethereum, but the gas costs are pinching you. 

A layer-2 network like Polygon with cheaper fees and faster speed is a popular choice. The following steps help you to understand how to bridge your Ethereum ETH to Polygon’s wrapped ETH.

Locking your coins

You connect your original coins’ wallet with the bridging smart contract. You then define how many coins you want to convert and provide the bridge with the destination asset and your receiving wallet’s public address.

Verifying the transaction

Once you commit and give the go-ahead to the bridge, it verifies that your coins have been received by the original blockchain’s smart contract, and the coins are now locked in the contract.

Minting equivalent coins on the new network

With your coins now locked in a dedicated wallet (operated by the smart contract), it triggers its counterpart on the other network. The destination smart contract then mints (the process of creating new coins or tokens) in equivalent value. These new coins will then be deposited in your destination wallet.

Use your new coins

With the new coins in your receiving wallet, you can spend them on the destination network. You can trade, provide liquidity, or partake in any service available on the destination chain.

Burn the coins to move back

The good thing is that the bridging runs both ways. When you are done with activities on the new chain, you can simply use the bridge to move back to the original chain. The process is the same, but the originating and destination chains are switched (and so is the receiving wallet address). 

Instead of locking up your new coins, this time the contract burns them (a process of sending coins to a wallet where they are unretrievable). 

Unlocking your original coins

When your new coins are burnt, this triggers a signal to the original chain’s smart contract. It releases your locked coins to your wallet, and you are good to go.

Avoid being rekt with these three golden rules

The bridging process, while easy when one learns it, has a few caveats. While the bridges use smart contracts to secure asset movements, they are not 100% secure. Some famous bridge attacks include the 2022 Ronin bridge exploit and the Poly Network 2021 attack.

Before you decide to bridge your assets across two blockchain networks, there are three things that you must be careful about.

Use the official bridge

Nearly every major network usually has one official bridge built by the people who maintain the network itself. These are the most reliable crypto bridges. 

While third-party bridges are often faster and cheaper, it is advisable to start the bridging experience with the official ones. They are generally considered the safest because they are tied directly to the network.

Triple-check the bridge URL

Always ensure that you are using the right website to access the bridge. Scammers create fake bridge websites that look identical to the real ones. This method, known as phishing, can convince the inexperienced (and even the experienced!) that the website is genuine. 

Unsuspecting crypto users can end up connecting their wallet to the website, and the smart contract can then be used to drain the wallet of all funds.

A test transaction is your best friend

Using a specific bridging service for the first time? Test it out. The saying, never put all your eggs in one basket is true here too. Never use all of your assets intended for the bridge in the first go. 

Bonus tip: Centralized exchanges free you of bridges

Normally, you cannot send a token directly from one blockchain network to another (for example, from ERC-20 on Ethereum to TRC-20 on Tron) because the blockchains don’t talk to each other directly.

However, many centralized exchanges (CEXs) allow you to deposit a token on one network and withdraw it on another. Here’s how that works:

• You send your token (e.g., USDT on ERC-20) to Binance (a CEX). USDT is a stablecoin issued by Tether.
• Now the exchange shows you USDT in your account balance.
• When you withdraw, you select TRC-20 as the withdrawal network.
• The exchange sends USDT from its Tron network balance to your wallet.

You pay normal withdrawal fees, but you don’t need a blockchain bridge tool. 

Also, remember that it is not a true cross-chain transfer happening on the blockchain itself. It’s the exchange acting as a middleman, using its own funds to complete the move for you. But this means you can effectively move value between networks without using a bridge service.

However, such an arrangement involves risks. For instance, if the exchange is hacked, freezes withdrawals, goes bankrupt, or blocks your account, you could lose access to your funds. You also depend on them supporting the right networks, and sending to the wrong network can still cause losses. 

In short, it’s convenient – but you’re relying on a company, not just the blockchain.

Common bridging mistakes (and how to avoid them)

Mistakes happen – everyone makes them. Here are some commonly occurring errors to look out for.

Enter the right wallet address

Wallet addresses (or public keys) are long alphanumeric characters that can be difficult to remember. Always manually verify the output address is correct. Don’t forget to ensure the wallet address is on the right network too.

Gas fees are applicable

Bridging services are just like any other crypto transaction and carry gas fees. Some bridges may charge a bit extra for the token swap services. Most reputable bridges show an expected output box, showing how many tokens you will receive on the other chain.

Gas fees are not a fixed value. These change depending on the network load or traffic. If you are not in a hurry, you can bridge your tokens when the network load is low and the gas fee is inexpensive.

Bridging can take time

If everything is done right and the bridge accepts your crypto, but doesn’t deposit it in the receiving wallet, don’t panic. Network load can cause delays as two different blockchains are involved, each with its own traffic.

When you initiate a bridging action, you may get a TX ID, or a transaction ID. Copy and paste it into a good block explorer to verify the transaction status. If it’s there and pending, your bridging is initiated and is waiting for confirmation.

Crypto bridges are an essential service

Crypto bridges provide essential financial infrastructure for different blockchains to interconnect. Not all networks are alike. Some are faster and cheaper, while others can have more users and services.

Without bridges, these networks would remain isolated islands, forcing users to keep different coins and tokens, and even the same coin with different versions for specific networks. This creates fragmentation and makes it difficult to handle assets.

Crypto bridges help to hold on to your favorite assets on your preferred chain, but still have access to other blockchain networks.

FAQs

How can I safely transfer crypto between different blockchain networks?

You can use a reputable crypto bridging service that supports your native blockchain and the destination network. Look for code audits of the bridges and their smart contract to make sure they are safe. Always test a small transaction first to make sure everything is working smoothly.

Can I move ERC-20 tokens to TRC-20 without using a crypto bridge?

You will need to use a crypto bridge if you are not going to use a centralized exchange (CEX) and transfer directly from your personal wallet. To use a centralized exchange, you must first ensure that the platform supports deposits and withdrawals of your selected assets on the Ethereum and Tron networks. You can deposit the tokens using your CEX account. Once the platform reflects it in your balance, you can initiate a withdrawal request and select the Tron network to receive these as TRC-20 tokens.

Can crypto bridges be hacked, and how can users protect their funds?

If a vulnerability exists in a bridge, it can be exploited by hackers. To keep yourself safe, always use the official or a reputable third-party bridge. A successful code audit will also let you know if the bridge is safe enough to use.

What fees should I expect when transferring crypto across different blockchain networks?

A gas fee is expected, since bridging is a transaction. The gas fee may vary depending on the network load, while a bridging service may also require a payment for using its services. A good and reputable bridge will show the expected gas fee and how many tokens you will be receiving in the destination wallet.