Decentralized mobile marketplace based on distributed ledger technology (DLT) for tokenized settlement of physical goods via escrow smart contract

Abstract

Decentralized marketplace system for processing purchase transactions of physical goods, including: a) a tokenization module that generates a non-fungible token for each physical product on a distributed ledger technology (DLT) and stores metadata of the token in a decentralized storage system; b) a marketplace program that provides at least functions for creating a listing, purchasing (buy_now), submitting shipping information (submit_tracking) and confirming delivery (confirm_delivery); c) an escrow smart contract which, upon triggering buy_now, locks a purchase token in an escrow vault, transfers a transaction fee to a fee vault, and immediately delivers the non-fungible token to the buyer; d) a carrier oracle that transmits a cryptographically signed delivery event with timestamp and nonce to the escrow smart contract, the smart contract verifying the validity of the delivery event by signature verification; e) a mechanism which, after successful verification of the delivery event, releases the purchase token locked in the escrow vault to the seller; f) a mobile front-end that communicates with the DLT via a wallet adapter interface, transfers image data to the decentralized storage for tokenization and provides the marketplace functions mentioned in b) to the user.

Description

1. Title of the invention

[0001] Decentralized mobile marketplace based on distributed ledger technology (DLT) for tokenized settlement of physical goods via escrow smart contract 2. Technical field

[0002] The present invention relates to the field of blockchain or distributed ledger-based trading platforms and in particular to the tokenization of real-world items (Physical-Item-NFTs), automated escrow processing and mobile user interaction via a mobile application preferably implemented across platforms, for example with Flutter. 3. State of the art

[0003] NFT marketplaces (e.g. OpenSea, Magic Eden) enable the trading of purely digital tokens, but lack a standardized procedure for the secure settlement of physical goods.

[0004] Escrow solutions in traditional e-commerce rely on central service providers who assume the trust between buyer and seller.

[0005] Smart contracts for trading SPL or ERC tokens already exist on distributed ledger technologies (e.g., Solana, Ethereum, Algorand), but so far there is no combination of: • Tokenization of physical goods, • automatic escrow management, • cryptographically verified proof of delivery (carrier oracle) and • Mobile front-end integration.

[0006] The lack of an integrated approach leads to increased risk for both parties, higher transaction costs, and a fragmented user experience. 4. Problem statement

[0007] The goal is to create a process and system that: • clearly represents physical goods as NFTs (Supply = 1), • locks the purchase price in a decentralized escrow smart contract, • the release of the purchase price is only permitted after verifiable delivery to the buyer, • the entire interaction is realized via a mobile application (Flutter), and • transaction costs and times reduced to a minimum, • without the need for a central intermediary. 5. Solution

[0008] The invention solves the above-mentioned problem by combining the following features: The NFT minting module (Metaplex Token Metadata Standard) generates a non-fungible token (Supply = 1) for each physical product on a distributed ledger technology (DLT), with the token's metadata stored on decentralized storage (IPFS / Arweave). Marketplace program (implemented in Anchor or a comparable DLT framework) provides suitable functions for the cases create_listing, buy_now, submit_tracking, confirm_delivery, rate_user and update_profile_nft. The Escrow Smart Contract (BuyEscSC) manages the purchase token in three states: • AwaitingShipment - after buy_now, the purchase token is transferred to the escrow vault. • AwaitingDelivery - after the seller has entered the tracking ID. • Delivered - after a cryptographically verified delivered event from the Carrier Oracle, the purchase token is released to the seller and the fee is transferred to the Fee Vault. Carrier Oracle delivers a signed delivered event (e.g., from Shippo / EasyPost). The payload is verified on-chain using secp256k1 verification or comparable technology (replay protection via nonce / timestamp). Rating and reputation accounts store ratings (0-5 stars) on-chain. Profile-NFT contains the encrypted CID of a Valid ID (KYC). Mobile front-end (preferably implemented with a cross-platform technology like Flutter) integrated: • Wallet adapter (Phantom, Solflare, Solana Mobile Wallet Adapter or any other DLT-compatible wallet interface) for transaction signature, • Camera upload → IPFS → NFT-Mint, • UI for listing, purchasing, tracking input, rating and display of the profile NFT. Governance mechanisms: Upgradeable program with multi-signature upgrade authority, rent exemption for all PDAs, and external security audits.

[0009] This combination creates a fully decentralized, automated marketplace where the risk for buyers and sellers is reduced to a minimum because payment is only made after cryptographically secured proof of delivery. 6. Examples of Implementation 6.1. System Architecture Table 1: System architecture of the decentralized marketplace component Description Technology (Example) On-Chain NFT minting, marketplace program, escrow contract, rating accounts, profile NFT Solana, Ethereum, Algorand(DLT Framework, Anchor,Rust / Move / Solidity) Off-Chain IPFS / Arweave gateway, KYC service (encryption), Carrier Oracle (webhook) Node.js / TypeScript, Express, secp256k1 Frontend Mobile App (Listing, Purchase, Tracking, Rating) Flutter (Dart), wallet adapter interface (Phantom, Solflare, etc.) Governance Upgrade Authority (Multi-Sig), Fee Vault DLT Program Derived Addresses (PDAs)

[0010] The schematic system architecture shows the data flows between the components. 6.2. Purchase process 1. NFT creation - The seller photographs the product, the app uploads the image to IPFS, generates the CID and calls the Mint program → non-fungible token with metadata is created. 2. Listing - The seller calls create_listing; the NFT is transferred to the escrow vault of the Marketplace program and the listing is stored in the on-chain state. 3. Purchase - The buyer selects the listing, calls buy_now; the purchase token (e.g. USDC, SOL or a custom-defined platform token, such as a project-specific utility token) is transferred to the BuyEscSC escrow vault, the fee (e.g. 2%) to the fee vault and the NFT immediately sent to the buyer's ATA. 4. Tracking input - The seller submits the tracking ID via submit_tracking. The status changes to AwaitingDelivery. 5. Proof of Delivery - The carrier oracle sends a cryptographically signed delivered event with a timestamp and a one-time-use nonce to the on-chain program. The contract verifies the signature, the nonce, and the timestamp. If successful, `confirm_delivery` is executed. 6. Payout - The purchase token is released to the seller's ATA, the fee remains in the fee vault. 7. Rating - Both parties can submit a rating (0-5 stars) via rate_user, which is stored in the reputation account.

[0011] The state transition graph of the escrow contract visualizes the described process. 6.3. Example code (excerpt) 6.4. Advantages over the state of the art Table 2: Comparison with the state of the art feature State of the art invention Trust mechanism Central service provider, manual release Fully on-chain, automatic release after cryptographic proof of delivery Tokenization of physical goods Mostly only digital assets Non-fungible token (Supply = 1) with IPFS metadata, unique assignment to the physical object Proof of delivery Manual entry, no trustless procedure Carrier Oracle delivers signed event, on-chain verification Mobile UX Web-only, no native camera integration Flutter app with direct image upload → NFT-Mint Fees High platform fees 2% (configurable), payment in USDC, SOL or proprietary token Governance No upgrade option Upgradeable program, multi-signature authority, rent exemption 7. Differentiation from known intellectual property rights: Regarding KR000102772492B1 - NFT SYSTEM FOR CONVERTING REAL ASSETS TO DIGITAL ASSETS USING BLOCKCHAIN-BASED NFT:

[0012] The intellectual property right relates to the tokenization of real estate and differs significantly in its applications. Regarding KR000102434838B1 - NFT Hybrid NFT Market System:

[0013] Describes a pure marketplace for non-fungible tokens and has no connection whatsoever to real existing physical goods. For KR000102456619B1 - SYSTEM FOR PROVIDING BLOCKCHAIN ​​BASED AUCTION ALLOCATING SERVICE FOR SECONDHAND TICKET:

[0014] Describes a marketplace for used tickets, is limited to trading used tickets and does not use an NFT component or an escrow smart contract.

Claims

[1] Decentralized marketplace system for processing purchase transactions of physical goods, comprising: a) a tokenization module that generates a non-fungible token for each physical product on a distributed ledger technology (DLT) and stores metadata of the token in a decentralized storage system; b) a marketplace program that provides at least functions for creating a listing, purchasing (buy_now), submitting shipping information (submit_tracking) and confirming delivery (confirm_delivery); c) an escrow smart contract which, upon triggering buy_now, locks a purchase token in an escrow vault, transfers a transaction fee to a fee vault, and immediately delivers the non-fungible token to the buyer; d) a carrier oracle that transmits a cryptographically signed delivery event with timestamp and nonce to the escrow smart contract, the smart contract verifying the validity of the delivery event by signature verification; e) a mechanism which, after successful verification of the delivery event, releases the purchase token locked in the escrow vault to the seller; f) a mobile front-end that communicates with the DLT via a wallet adapter interface, transfers image data to the decentralized storage for tokenization and provides the marketplace functions mentioned in b) to the user. [2] The system according to claim 1, characterized by that the carrier oracle transmits an event provided by a shipping service provider and the escrow smart contract releases the purchase token only if the event contains a signature, a one-time use nonce, and a valid timestamp. [3] The system according to claim 1, characterized by that the Carrier Oracle uses a webhook interface provided by a shipping service provider to generate the delivery event. [4] The system according to claim 1, characterized by that the tokenization module uses a standardized NFT metadata standard, in particular the Metaplex token metadata standard or an equivalent standard of another distributed ledger technology. [5] The system according to claim 1, characterized by that the transaction fee is paid in a common crypto value token (e.g. USDC, SOL) or in a specially defined platform token. [6] The system according to claim 1, characterized by , that a profile NFF is generated which contains an encrypted Content Identifier (CID) from a Know Your Customer (KYC) database. [7] The system according to claim 1, characterized by, that the marketplace program includes a rating module that provides a rating scale from 0 to 5 stars and stores the ratings in an on-chain reputation account. [8] The system according to claim 1, characterized by that the marketplace program is designed to be upgradeable and uses a multi-signature upgrade authority. [9] The system according to claim 1, characterized by that all Program-Derived Accounts (PDAs) generated by the Marketplace program are designed to be rent-exempt. [10] The system according to claim 1, characterized by that the mobile front-end is implemented with a cross-platform technology, specifically Flutter, and supports both iOS and Android devices.