Why fraud doesn't pay

Any program that pays people for doing something attracts people who try to fake it. GPS games get spoofed. Photo-based receipt apps get edited images. RECEIPT is designed so that faking it costs more than it earns.

The core idea

To earn a reward on RECEIPT you need a real receipt, signed by the merchant, for a real payment. The reward is a share of a daily pool, capped at 5 % of eligible spend. So the only way to earn is to spend real money, and the most that comes back is a small part of what you spent, paid in a Stock Token whose price can go down. Buying something only to farm rewards loses money by construction.

To cheat, you would have to spend real money to get back a fraction of it.

Attack by attack

• Forged receipts. Every receipt needs a valid DKIM signature from a registry domain. Changing one character of the signed content breaks it.
• Someone else's receipts. A receipt only counts if it was addressed to one of your verified emails, and each email can belong to one account only.
• Claiming the same order twice. Each order produces a unique fingerprint that can be claimed once, worldwide, and the email's Message-ID must be new too.
• Buy, claim, refund. Rewards vest for 30 days, and a refund email from the same merchant cancels the matching rewards.
• Gift cards and top-ups. Gift cards, prepaid reloads, crypto purchases and donations are excluded.
• Old receipts. Receipts older than 7 days when they reach us don't earn rewards.
• Many accounts. Each account needs its own real purchases, and unlocking rewards needs the $RECEIPT membership threshold in each wallet. Rate limits and clustering alerts watch the rest.
• Tricking the parser. The amount we extract must appear, exactly as written, in the signed part of the email. Low-confidence reads go to manual review.

Caps that keep it boring

On top of the checks, simple limits make large-scale abuse pointless: each receipt counts for at most $200, each user can submit up to 10 receipts a day, and monthly caps per merchant and per user will be published at launch.

Rejections come with a reason

Every receipt that doesn't count comes back with the reason: broken signature, unknown sender, too old, already claimed or excluded. Honest mistakes are easy to understand and fix, and trial and error teaches a cheater only one thing: the rules hold.

Protecting the pool itself

Fraud is not only about receipts; the money side has its own guards. The vault that holds the pool is owned by a multisig wallet. The key that buys Stock Tokens every night can only trade within daily limits and can be paused. Every purchase uses a maximum price derived from the Chainlink feed, and thin pools are skipped instead of forced.

Why this matters to honest users

Every fake receipt that got through would take a slice of the pool from people who bought something real. Making fraud unprofitable is how the daily rate stays meaningful for everyone else. It is also why we never ask for your bank login, your location or a photo of your face: the receipt is the proof, and the math does the rest.