Hemi uses a technology called tunnels to manage cross blockchain connectivity. But how did users used to bridge Ethereum and Bitcoin?

Blockchains are usually closed systems. Bitcoin runs on its own chain. Ethereum runs on a different one. Assets and data on one chain cannot move to another on their own. This creates a problem for users and developers who want to interact across multiple networks. That is where crypto bridges come in.

A crypto bridge is a tool that connects two separate blockchains. It lets assets or information pass between them. This allows users to move value from one chain to another, or access features that are only available on a different network. For example, a user might want to use their Bitcoin on an Ethereum-based DeFi platform. A bridge makes that possible by creating a link between the two chains.

Bridges work by using a system of locking and minting. When a user wants to move an asset from one blockchain to another, they send it to a smart contract or address on the original chain. That contract holds the asset securely and then triggers the creation of a mirrored or wrapped version of that asset on the destination chain. The original asset stays locked and cannot be used until the user brings back the wrapped version and unlocks the original.

This process creates a synthetic version of the asset on the new chain. For example, if you send Bitcoin to a bridge that connects to Ethereum, the bridge will hold the Bitcoin and issue a token on Ethereum that represents it. This token can now be used in Ethereum applications. When you are done, you can return the token to the bridge and redeem the original Bitcoin.

Some bridges use a trusted third party to hold the funds and manage the minting process. Others use more decentralized systems that rely on multi-signature wallets or smart contract logic. The more decentralized the bridge, the more secure and censorship-resistant it tends to be. However, decentralized bridges can be more complex to build and operate.

There are also risks with bridges. If the bridge’s code has bugs or the system is not properly secured, assets can be lost or stolen. This has happened in several high-profile cases. Because bridges involve two different chains and often rely on off-chain coordination, they can be a target for attackers. That is why bridge design is one of the most important problems in blockchain infrastructure today.

At Hemi, bridges are treated as a foundational part of how Bitcoin connects to other chains. Hemi uses a system called cross-chain tunnels to enable movement of assets and data between Bitcoin and Ethereum-compatible environments. These tunnels use a combination of cryptographic proofs and economic incentives to ensure that assets are transferred securely and without trust in a single party.

The advantage of Hemi’s approach is that it avoids putting full trust in third parties while still keeping the bridge usable and efficient. Instead of relying on a central custodian, Hemi uses a modular consensus system that verifies activity on both ends and anchors the results to Bitcoin. This gives developers and users confidence that cross-chain activity will remain secure and transparent.

Crypto bridges are one of the most important tools for making blockchains interoperable. They allow assets and applications to move beyond the limits of a single network. As the industry matures, bridges will continue to evolve, with better security models, faster transfers, and deeper integration into the user experience.

If Bitcoin is to remain a key part of the broader crypto ecosystem, it needs secure ways to connect with other chains. Bridges make that possible. Platforms like Hemi are leading the way by building cross-chain tools that are rooted in Bitcoin’s values and designed for long-term scalability.