This ERC proposes a standard schema for digital receipts of transactions. Digital Receipt Non-Fungible Tokens are issued by a vendor when a customer makes a purchase from their store and contains transaction details necessary for record keeping. Digital Receipt Non-Fungible Tokens extend ERC-721 which allows for the management and ownership of unique tokens.
Purchases from online retailers include a receipt that is emailed and/or physically provided to the customer. These receipts are critical for many reasons but are provided in an analogue form which is difficult to parse by financial systems. Digital receipts have never gained traction dispite the fact that point of sales systems are already digital and the customers often want this information in their own digital systems. So we are left with a redundant Digital -> Analogue -> Digital process which requires unnecessary data entry or the use of clunky receipt-scanning applications.
Digital receipts are relatively simple and can be specified with a schema that can be parsed into JSON or other structured formats. In addition we can prove the receipts validity by digitally signing the receipt using the vendors private keys.
As Ethereum scales tooling will need to be developed to provide end users with features (such as receipts) already available to fiat transactions. NFTs provide a unique opportunity to link an on chain purchase with its transaction details directly through the transaction state update. If we conceptually think of a transaction as funds provided to one participant and goods provided to another, then our real life state includes two sides of a transaction, 1) Funds changing ownership and 2) goods changing ownership. NFT receipts are first class citizens of a transaction reflecting the goods changing ownership as part of the transaction state. They will bring our on chain transaction state in line with the changes happening in the real world.
The convenience of a direct link to the transaction receipt via the transaction state is significant, other methods of distributing receipts either off chain or through smart contracts separate to the initial transaction lose this link and force the end user to manually locate the transaction details when needed. The benefit can be demonstrated by comparing a wallet that allows a user to click through a transaction to its receipt (available immediately after purchase without any further action) verses a user needing to search through a datastore to locate a receipt for a transaction that they can see in their wallet history.
Digital receipt as NFTs can also conceptually include other important information such as item serial numbers and delivery tracking etc.
One of the major roadblocks to fully automating our finance world has been the difficulty in tracking transaction details. Human beings physically tracking paper receipts is archaic and NFTs on the blockchain provide a pathway for these systems to be significantly improved.
Transaction Flow:
The JSON schema is composed of 2 parts. The root schema contains high level details of the receipt (for example Date and Vendor) and another schema for the optionally recurring line items contained in the receipt.
The schema introduced complies with ERC-721's metadata extension, conveniently allowing previous tools for viewing NFTs to show our receipts. The new property "receipt" contains our newly provided receipt structure and the signature property optionally allows the vendor to digitally sign the receipt structure.
This standard is an extension of ERC-721. It is compatible with both optional extensions, Metadata and Enumerable, mentioned in ERC-721.
The data stored in the digital receipt includes various types of personally identifying information (PII), such as the vendor's name, contact details, and the items purchased. PII is sensitive information that can be used to identify, locate, or contact an individual. Protecting the privacy of the customer is of utmost importance, as unauthorized access to PII can lead to identity theft, fraud, or other malicious activities.
To ensure the privacy of the customer, it is crucial to encrypt the PII contained within the digital receipt. By encrypting the PII, only authorized parties with the appropriate decryption keys can access and read the information stored in the digital receipt. This ensures that the customer's privacy is maintained, and their data is protected from potential misuse.
While encrypting PII is essential, it is important to note that defining a specific encryption standard is beyond the scope of this ERC.
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