Pay Like Sending an Email

Send crypto to an email address or phone number. No wallet address needed. No QR codes. Just type and send.

Blockchain Addresses Are Not Human-Readable

Blockchain addresses like 0x7a3b...4f2c are not designed for humans. They cannot be spoken aloud, cannot be remembered, and are easy to mistype. Sending a transfer requires copying 42-character hex strings — a process that is error-prone and intimidating for mainstream users.

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Not Speakable

Try telling someone your Ethereum address over the phone. Hex strings are designed for machines, not conversations.

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Easy to Mistype

One wrong character sends funds to a non-existent address. No confirmation, no reversal. Funds are permanently lost.

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Copy-Paste Attacks

Clipboard malware replaces copied addresses with attacker-controlled ones. A common vector for theft that is invisible to the user.

Intent-Based Payment Flow

HFI-Pay uses an intent-based architecture. The sender expresses a payment intent using a human-readable identifier, and the protocol handles discovery, locking, verification, and settlement.

Send Flow

Sender email + amount
→
Payment Intent locked on-chain
→
Notification recipient alerted
→
Claim verify + receive

The sender specifies the recipient by email or phone number and the amount. The system creates a payment intent that is locked on-chain, bound to the recipient's DiscoveryID (HMAC-derived from their identifier). The recipient receives a notification, verifies their identity, and claims the funds. If unclaimed after a timeout period, the sender can reclaim.

Claim Flow

The recipient does not need a pre-existing wallet. When they verify their identity (email or phone), the system discovers or creates their on-chain identity via VA-DAR and releases the locked funds to their account. The first payment someone receives can also be their wallet creation event.

Cross-VM Payment Support

HFI-Pay intents can target multiple VMs within ACE Chain. When you pay to an email address, the recipient receives tokens on their preferred VM — EVM, SVM, or any other supported execution environment.

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VM-Agnostic Intents

Payment intents are not bound to a specific VM. The recipient's preference determines where the funds land. Same payment, flexible delivery.

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Unified Token Ledger

Because all VMs share one token ledger, cross-VM payments are just balance changes. No wrapping, no bridging, no conversion fees.

ZK Claim Verification

Claims are verified using zero-knowledge proofs. The recipient proves ownership of the identifier (email or phone) without revealing it on-chain. The verification happens off-chain, and only the proof is submitted for settlement.

Claim Verification // Recipient proves: "I own identifier X" // Without revealing: X itself ZK Proof = prove( public: DiscoveryID, // HMAC(secret, identifier) private: identifier, secret // never revealed on-chain ) // Verifier checks: // 1. HMAC(secret, identifier) == DiscoveryID ✓ // 2. Proof is valid ✓ // 3. Release funds to recipient's idcom ✓

This ensures that the on-chain record contains no human-readable information. An observer sees a DiscoveryID and a ZK proof — they cannot determine which email address or phone number was used.

Privacy by Design

HFI-Pay is built with privacy as a core requirement, not an afterthought. Payment intents are bound to DiscoveryIDs (HMAC-derived), not plaintext identifiers. On-chain observers cannot determine the human-readable recipient of any payment.

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No Plaintext on Chain

Email addresses and phone numbers never appear on-chain. Only HMAC-derived DiscoveryIDs are stored, which are computationally irreversible.

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Unlinkable Payments

Without the HMAC secret, observers cannot link a DiscoveryID to a real-world identity. Payment history is visible but attribution-resistant.

Use Cases

HFI-Pay transforms blockchain payments from a technical operation into a human-friendly experience. The same UX patterns that made email ubiquitous — type an address, hit send — now work for value transfer.

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Person-to-Person

Split a dinner bill, pay back a friend, send a gift. Just type their email and the amount. No QR codes, no address books, no friction.

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Merchant Payments

Customers pay to a merchant's email address. No payment processor integration needed. Settlement is instant and on-chain.

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Payroll

Pay employees by email address. No need to collect wallet addresses. Employees receive funds and can set up their wallet when convenient.

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Airdrops

Distribute tokens to an email list. Recipients do not need wallets to be eligible. They claim when ready, creating their wallet in the process.

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Cross-Border Remittance

Send money across borders using a phone number. Sub-cent fees and instant settlement make micro-remittances economically viable for the first time.

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AI Agent Payments

AI agents can send and receive payments using identifiers. Combined with ACE Chain's sub-cent fees, this enables autonomous economic agents at scale.

Read the HFI-Pay Research

Technical specification of the human-friendly payment protocol with ZK claim verification.