Blockchain bridges are built to connect networks that cannot natively communicate, allowing assets and data to move across separate blockchain ecosystems. Each chain has its own rules, token standards, and smart contract environment, which is why BTC cannot be used directly on Ethereum and ETH cannot be transferred straight onto the Bitcoin network.
That lack of native interoperability creates friction for both users and developers. For users, the clearest example is payments or asset transfers across chains. For developers, bridges open the door to cross-chain dApps that interact with more than one blockchain. Without a bridge, someone holding BTC would still need an extra conversion step if the receiver only accepted ETH.
How a bridge typically moves tokens between chains
The most common bridge model is simple in concept: lock the original asset on the source chain, then create an equivalent version on the destination chain. In some designs, assets may also be burned before the new representation is issued. The token on the destination network tracks the value of the original asset while becoming usable in a different ecosystem.
The source material uses Bitcoin as the core example. A bridge can lock 1 BTC on Bitcoin’s main chain and mint Wrapped BTC, or WBTC, on Ethereum. WBTC follows the ERC20 token standard, making it compatible with Ethereum wallets and applications. It remains pegged to bitcoin’s value and can later be unwrapped for an equivalent amount of BTC.
Bridges are not limited to token transfers. They can also connect a parent blockchain with a sidechain, making interoperability possible even when the two networks rely on different consensus mechanisms.
Trusted bridges and trust-minimized bridges
Most bridge designs fall into two broad groups: trusted bridges and trust-minimized bridges.
Trusted bridges are custodial. They rely on counterparties to validate transactions and hold the assets being bridged. Users depend on the operator’s reputation and operational security. The article points to WBTC as an example of this structure, with the corresponding BTC held in custody by BitGo. The trade-off is clear. If the central operator is hacked, goes bankrupt, or faces another major disruption, assets under custody may be exposed.
The Ronin Bridge Protocol exploit shows that risk in practice. According to the source, attackers exploited a vulnerability and stole more than $600 million in ETH and USDC, highlighting how a trusted bridge can become a single point of failure.
Trust-minimized bridges take a different route. These are non-custodial systems that use smart contracts, algorithms, and economic incentives to secure cryptoassets. In this model, users rely less on a central entity and more on code. Nexus and Gravity are listed as examples. That does not remove risk; it shifts it. If the code or incentive structure is flawed, losses can still happen quickly.
Examples of major blockchain bridges
Several bridge services are already widely known across the market. Binance Bridge allows selected cryptoassets to be converted into wrapped tokens for use on BNB Smart Chain, including BTC, LTC, ETH, LINK, ATOM, and DOT. Avalanche Bridge supports ERC20 transfers between Ethereum and Avalanche. The source says Ethereum transactions take around 10 to 15 minutes to process, while Avalanche transactions take only a few seconds, with fees paid in AVAX.
Horizon Bridge supports digital asset transfers among Ethereum, BNB Smart Chain, and Harmony, with assets exchanged on a 1:1 basis and later redeemed back to the original chain. Polygon Bridge connects Polygon and Ethereum through the Polygon (PoS) Bridge and the Plasma Bridge, supporting ERC20 tokens and NFTs. Wormhole began as a bridge between Solana and Ethereum, and its site describes it as a general message-passing protocol linked to Ethereum, Solana, Terra, BNB Smart Chain, Polygon, Avalanche, Oasis, Fantom, Karura, Celo, Acala, Aurora, and Klaytn. It verifies data and asset transfers through a node network before submitting them to the target chain.
Interoperability matters, but bridge risk remains central
Cross-chain connectivity is important for a multi-chain industry, but bridges come with real security trade-offs. Trusted bridges carry centralization risk. Trust-minimized bridges depend heavily on code quality. The article also cites the Wormhole hack, where attackers stole more than $300 million.
Before using any bridging protocol, the source recommends checking documentation, reviewing code, and assessing the maturity of the protocol. Bridges may solve interoperability problems, but the structure behind each bridge still determines how much risk users take on.