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Hemi: A Modular Layer-2 Supernetwork Unifying Bitcoin and Ethereum

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@haimon_wake⁠

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Background: Bitcoin and Ethereum

It is well-known that Bitcoin and Ethereum have long existed in isolation from one another, yet the opportunities between them remain immensely compelling.

Bitcoin was created as a system for value transfer and payments, with minimal design and maximum security.

Ethereum, on the other hand, was envisioned as the “World Computer,” built on an account-based model with a Turing-complete EVM.

There is a common principle: the more complex a system becomes, the more potential attack surfaces it introduces. Bitcoin deliberately stayed simple, while Ethereum expanded expressiveness.

In addition, Bitcoin and Ethereum use entirely different consensus mechanisms and data structures. Their block formats, state models, and validation rules are incompatible — like two people speaking completely different languages.

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Existing Attempts at Interoperability

Given these differences, the community has experimented with several approaches. A typical one is Wrapped Bitcoin (wBTC):

Users deposit BTC with a trusted custodian (e.g. BitGo).

The custodian then mints an equivalent amount of wBTC on Ethereum.

The risk here is clear: centralization. Custodians can misbehave, get hacked, or face regulatory seizure.

Other transitional approaches include RSK’s multisig bridge and Merlin’s Layer-2, but they all involve some degree of trust or encapsulation.

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Enter Hemi

Hemi’s vision is not to build just another cross-chain bridge. Instead, it aims to transform Bitcoin into an active, programmable infrastructure within a familiar EVM environment.

Programmability: Proof-of-Proof (PoP) Consensus

Hemi introduces programmability to Bitcoin through PoP consensus and its Hemi Virtual Machine (hVM) plus the Hemi Bitcoin Toolkit (hBK).

Developers can use standard tools like Solidity to build EVM-compatible applications that are natively aware of Bitcoin state.

Superfinality: Anchoring into Bitcoin

Through PoP, Hemi transactions achieve Bitcoin-grade finality in ~90 minutes.

In Bitcoin, a transaction is typically considered safe after ~6 confirmations (~1 hour).

In Ethereum, finality usually takes two epochs (~12 minutes).

In Hemi, once a block is written into Bitcoin via PoP and confirmed in ~9 blocks (~90 minutes), reversing it would require a 51% attack on Bitcoin itself.

Compared to typical L2s or sidechains (which rely on their own consensus or week-long challenge periods), Hemi’s PoP offers unmatched security guarantees in a shorter timeframe.

Portability: Hemi Tunnels

Cross-chain asset movement is inevitable in a multi-chain world. But most bridges introduce centralized trust assumptions, and have been frequent attack targets (e.g. Ronin, Wormhole).

Hemi addresses this with Tunnels, a trust-minimized portability system:

For Bitcoin: a dual-vault model

High-value vaults rely directly on Bitcoin’s security, powered by BitVM (an off-chain computation + on-chain fraud proof model inspired by Optimistic Rollups).

If someone submits a fraudulent withdrawal, any honest participant can post a fraud proof on Bitcoin and block it.

Security assumption: 1-of-n honest participants is sufficient.

Low-value vaults use multisig + overcollateralization. Validators manage funds but must stake collateral on Hemi/Ethereum. If they misbehave, their collateral is slashed to compensate users.

For Ethereum: an Optimistic Rollup–like bridge.

Hemi publishes its data to Ethereum. Withdrawals undergo a challenge window.

But once Hemi blocks achieve PoP superfinality on Bitcoin (~90 minutes), the Ethereum challenge window can be shortened since Bitcoin already backs security.

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Roadmap, Team, and Token

Currently, Hemi operates as an Optimistic Rollup, executing transactions on Hemi while posting data to Ethereum. The roadmap includes transitioning into a ZK Rollup, once BitVM integration and ZK support are complete.

$HEMI Token

Total Supply: 10,000,000,000

Distribution:

Community & Ecosystem: 32% (3.2B)

Investors & Strategic Partners: 28% (2.8B)

Team & Core Contributors: 25% (2.5B)

Hemispheres Foundation: 15% (1.5B)

Utility

Staking & Security: Sequencers, publishers, and challengers must stake HEMI; slashing enforces honest behavior.

Governance: Staked HEMI grants governance rights (veHEMI).

Gas & Fees: ETH is supported, but HEMI is the preferred gas token with potential discounts.

PoP Mining Incentives: HEMI is minted to reward PoP miners for publishing Hemi state into Bitcoin, covering BTC transaction fees and providing profit.

Cross-chain Collateral: HEMI serves as collateral for liquidity within Tunnels.

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Why Hemi Is Different

Competing protocols like Stacks, RSK, and Merlin require some form of bridging or wrapped BTC. Their smart contracts ultimately operate on representative assets, not Bitcoin itself.

By contrast, Hemi’s hVM allows contracts to directly query Bitcoin state:

“How many confirmations does this native Bitcoin transaction have?”

“List all UTXOs of this Bitcoin address.”

This enables:

A trust-minimized on-chain escrow service, where native BTC is released based on EVM-verified conditions.

Collateralized lending using native UTXOs directly, without wrapping BTC into wBTC or equivalent.

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Conclusion

In plain terms: Hemi allows smart contracts to interact directly with native Bitcoin, rather than with wrapped assets like wBTC.

If the technical complexity can be effectively managed, Hemi’s potential application space is fundamentally broader and more trust-minimized than competing approaches.

That said, the long-term implementation remains to be proven. It’s worth keeping a close eye on how the project evolves.

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