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Live BB84 mainnet · Chain ID 42069000

Post-quantum infrastructure for Ethereum.

Hadamard builds BB84 — a Layer 2 rollup secured entirely by hash-based signatures. No elliptic curves, no ECDSA: built to stay secure when quantum computers arrive.

Download on the App Store Explore bb84.com →
Technology

The first hash-only Layer 2

Today's blockchains rely on elliptic-curve signatures that a large quantum computer could break with Shor's algorithm. BB84 replaces them with hash commitments — the most conservative primitive in cryptography.

ECDSA-free by design

Every transaction is authorised by revealing a hash pre-image, not by an elliptic-curve signature. There is no public key for a quantum attacker to invert.

One-time addresses

Funds live on single-use addresses (OTAs) derived from hash chains, so addresses are never reused and payments stay unlinkable by default.

Secured by Ethereum

BB84 is an OP Stack rollup: transaction data is posted to Ethereum mainnet as blobs, and withdrawals settle through Ethereum's fault-proof system.

BB84 Wallet

Post-quantum money in your pocket

A self-custodial wallet for the BB84 network. Your keys are generated and stored only on your device.

  • ETH, USDC and EURC — bridge between Ethereum and BB84 in a few taps.
  • Pay by username — send to names like swift-moon.bb84.eth instead of long addresses.
  • Buyer protection — choose Friends & Family or Goods & Services per payment.
  • QR, recurring and merchant payments — scan to pay, schedule transfers, check out in shops.
Download on the App Store

Available for iPhone and iPad.

BB84 Wallet welcome screen: self-custodial wallet secured by hash commitments
BB84 Wallet send screen with username recipient and USDC amount
BB84 Wallet key setup: your keys, your control
Developers

Build on BB84

A REST API with free keys, full Ethereum JSON-RPC and open-source tooling. Accept post-quantum payments in your shop or app.

# Network
RPC       https://bb84.com/rpc
Chain ID  42069000
Stack     OP Stack rollup · Ethereum L1
Assets    ETH · USDC · EURC

# REST API — get a key at bb84.com/developer
curl https://bb84.com/v1/status \
  -H "X-API-Key: bb84_live_YOUR_KEY"
Developer APIAPI keys, endpoints and limits
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Accept paymentsMerchant integration and checkout widget
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DocumentationHow the hash-only rollup works
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GitHubSource code and examples
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Company

About Hadamard

Hadamard Corporation develops quantum-secure systems, software and services. Named after the mathematician Jacques Hadamard, whose gate sits at the heart of every quantum circuit — and of the BB84 protocol our network is named after.

Albuquerque, USACorporate headquarters
Bonn, GermanyRegistered office
Leadership Investor relations Careers News
AlbuquerqueHeadquarters BonnRegistered office

Talk to us

Questions about BB84, partnerships or integrating post-quantum payments? Our team is happy to help.

Contact Hadamard info@hadamard.com