Hash Chain

Go in public. Come out private.

The privacy Layer 0.

Website  |  X  |  Protocol spec  |  HIPs  |  XMR swap model  |  Brand kit

Status: pre-launch, spec stage. Everything here is a draft and may change. Nothing is deployed, audited or available to use yet.

Hash Chain is a privacy-first Layer 0 network. It has its own validators, and privacy is built into the base layer, so accounts, payments, swaps, assets and apps are private by default, settle in moments, and connect to Ethereum, Base, Robinhood Chain and Monero. It is the private base layer for onchain finance.

1. Private accounts. Balances and history are hidden by default. One account holds any connected asset.
2. Private payments. Private transfers of ETH and stablecoins, payment links, batch payouts and merchant checkout.
3. Private swaps. A native exchange layer where trades, sizes and wallets are not visible, so no front-running or copy-trading. Includes native atomic swaps with Monero.
4. Private assets. Issue and hold tokenized assets, such as stablecoins and tokenized stocks, with private balances and transfer rules enforced by proofs.
5. Private apps. Deploy contracts whose inputs and state stay hidden. SDK and APIs for wallets, fintechs and apps.
6. Proofs, not exposure. View keys and credentials for audits, compliance checks and taxes. Private, not shady.
7. Connected to everything. Ethereum, Base, Robinhood Chain and Monero connect in and out.

Short versions. Full definitions are in the glossary.

• Layer 0. A base network that other networks plug into. Hash Chain is one, with privacy as a base-layer property.
• Shielded account. An account whose balances and history are hidden by default.
• View key. A read-only key that lets a chosen person see a scoped part of your history. It cannot spend.
• Connection. A door between Hash Chain and Ethereum, Base, Robinhood Chain or Monero.
• HIP. A Hash Chain Improvement Proposal, a public design document that proposes one change.

• Its own validators. An independent validator set secures the network by staking ETH.
• Proofs, not trust in contents. Validators verify zero-knowledge proofs without seeing amounts or parties.
• Fast deterministic finality is the design target.
• Fees in ETH. No token is required to use the network.
• Connections. Ethereum, Base and Robinhood Chain connect through contracts verified by the validator set, plus a liquidity network for fast transfers. Monero connects through trustless atomic swaps.

flowchart LR
    ETH["Ethereum"] <--> HC(("Hash Chain<br/>Layer 0"))
    BASE["Base"] <--> HC
    RH["Robinhood Chain"] <--> HC
    XMR["Monero"] <--> HC
    VAL["Validator set<br/>(stakes ETH)"] --- HC

• People who want to stop being tracked and pay and hold privately.
• Traders who want to trade without being front-run or copied.
• Businesses and fintechs that pay suppliers and staff, run treasury and accept payments without publishing finances, and can still prove them to auditors.
• Builders who want private apps without inventing cryptography.
• Monero holders who want to reach the Ethereum world without an exchange.

Phases are an order of work, not a schedule. No phase has a date.

The full roadmap is in the protocol spec.

• New to the project: read the overview and the FAQ.
• Unfamiliar term: check the glossary.
• What you would be trusting: security and trust and the threat model.
• A proposed change to the design: browse the HIPs.

• protocol-spec: the written design of Hash Chain, a draft, with research notes.
• hips: Hash Chain Improvement Proposals, the place where changes to the design are proposed and argued in public.
• xmr-swap-model: a research model of the ETH and XMR atomic swap. Not a working swap. Do not use with funds.
• brand-kit: logo, colors and typography for referencing Hash Chain.

Hash Chain is at the spec stage, so careful criticism is the most useful contribution.

• Ask about something unclear in the spec with a spec question.
• Suggest a change to a spec document with a spec change issue.
• Propose a design change through a HIP. Start from an idea issue and discuss it in public first.
• Fix typos and broken links with a pull request in the repository concerned.

The trust model, risks and open design questions are documented in the security and trust spec. To report a vulnerability, open a private security advisory on the protocol-spec repository.

• Website: https://hashchain.network
• X: https://x.com/hashchainL0
• Protocol spec: https://github.com/HashChainL0/protocol-spec
• HIPs: https://github.com/HashChainL0/hips
• XMR swap model: https://github.com/HashChainL0/xmr-swap-model
• Brand kit: https://github.com/HashChainL0/brand-kit
• Latest release: v0.2.0 draft specification (changelog)