| CCIP Number | 006 |
|---|---|
| Title | CityCoins VRF |
| Author(s) | Jason Schrader [email protected] |
| Consideration | Technical |
| Type | Standard |
| Status | Ratified |
| Created | 2022-03-16 |
| License | BSD-2-Clause |
The Stacks blockchain is a Layer 1 blockchain connected to Bitcoin, in which miners spend Bitcoin to bid for and win a fixed amount of Stacks tokens. Stackers have the option to lock up Stacks tokens for a specified amount of time, and in turn, receive a portion of the Bitcoin spent by miners proportionate to the amount Stacked1.
Taking this concept a level further, a new token (a "CityCoin") is created on the Stacks blockchain, following the SIP-010 fungible token standard2, such that CityCoins can be mined and Stacked per the methods stated above except a portion of the miner's bid would be redirected to the city's wallet overseen by a trusted third party custodian.
CityCoins leverage similar properties from the Proof of Transfer (PoX) consensus mechanism3 of the Stacks blockchain, programmed through a smart contract in Clarity.
This proposal describes the verifiable random function (VRF) used to calculate the block winner for a CityCoin.
The VRF contract is used to determine the winner of a mined block.
Through the get-random-uint-at-block function, the contract:
- fetches the on-chain VRF proof from the block height
- converts the lower 16 bytes into a uint
- returns the random integer
More information on Stacks block assembly can be found in SIP-005.
None, this is the initial implementation.
None, this is the initial implementation.
citycoin-vrfdeployed on the Stacks mainnet4, implementing theget-random-uint-at-blockfunction on lines 05-15