TrustDrop Protocol
Fair exchange for encrypted files
TrustDrop is a protocol for exchanging encrypted files without relying on seller promises. It combines on-chain escrow, zero-knowledge proof verification, data availability checks, and buyer recovery logic into one exchange flow.
Current prototype: contracts run on Arbitrum Sepolia, encrypted assets are stored on Walrus Mainnet, and proofs are generated with SP1 Prove Network.
Guarantees
Escrowed payment
Buyer payment is locked in an exchange channel until the protocol reaches settlement or refund.
Proof-backed fulfillment
Seller fulfillment is tied to VSS and VDD verifier contracts rather than a plain off-chain claim.
Buyer recovery
The buyer can recover the encrypted asset using wallet-derived or manually supplied purchase secrets.
Core Components
| Component | Role |
|---|---|
ExchangeHub | Creates channels and emits canonical marketplace events. |
ExchangeChannel | Stores sales, pending exchanges, fulfillment state, settlement, and refund logic. |
| VSS | Verifiable Secret Sharing path for buyer access to the data key. |
| VDD | Verifiable Data Delivery path for encrypted Walrus asset availability. |
| Oracle | Reports Walrus blob visibility for the current prototype. |
Applications
Fair File Marketplace is the first buyer-facing application built on TrustDrop. It is an application of the protocol, not the protocol itself.