Overview
Mystery Gift needed verifiable randomness for gacha-style reward systems without paying for a fully on-chain VRF path on every pull. The result is an offchain randomness API that runs inside Intel TDX, returns an attested result, and stores proof material on Arweave.
How It Works
- A client requests randomness from the API.
- The service generates the value inside an Intel TDX trusted execution environment.
- The response includes hardware attestation showing the request was processed by the expected code.
- Proof material is written to Arweave so users can inspect the result later.
Hard Parts
The engineering tradeoff is narrow but useful: this is not a smart-contract VRF replacement. It is for offchain gaming systems where the product needs public fairness evidence, but not direct EVM consumption by a contract.
Results
The writeup models Mystery Gift at 1,000 daily pulls and compares the TEE-backed approach against Switchboard and Chainlink-style VRF. The result is a much cheaper verifiable randomness path for the intended gacha-game use case.
