Skullcoin Labs — Encrypted NFT Contracts (eNFT)

Smart contracts powering Encrypted NFT (eNFT) primitive and the Seed Phrase Hunt game mode on Stacks (Bitcoin L2).

NFTs with two layers: public metadata visible to everyone, and a private payload accessible only to the current owner.
This enables incomplete-information games on-chain — negotiation, bluffing, and strategy that transparent ledgers normally make difficult.

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What’s inside

Contract	Purpose
skullcoin-competitive-seed-base	Core game logic — minting, burning, payouts, sale control
skullcoin-competitive-seed-phase1	Phase 1 NFT collection (base tier)
skullcoin-competitive-seed-phase2	Phase 2 NFT collection (upgrade tier, created via Phase 1 burns)

Seed Phrase Hunt (game mode)

Each NFT carries a hidden BIP-39 seed phrase word as its private payload. Players mint, trade, and negotiate to assemble a complete phrase that unlocks a prize.

Upgrade loop: burning 5× Phase 1 NFTs → mints 1× Phase 2 NFT, creating a deflationary “merge” mechanic that makes rarer payloads harder to obtain.

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Deployed contracts (Mainnet)

Replace the links below with the exact Hiro Explorer URLs that open correctly.

• Base Contract: SP3T54N6G4HN7GPBCYMSDKP4W00C45X19GQ4VT13Y.skullcoin-competitive-seed-base

• Phase 1 NFT: SP3T54N6G4HN7GPBCYMSDKP4W00C45X19GQ4VT13Y.skullcoin-competitive-seed-phase1

• Phase 2 NFT: SP3T54N6G4HN7GPBCYMSDKP4W00C45X19GQ4VT13Y.skullcoin-competitive-seed-phase2

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Contract API

Game control (owner-only)

Function	Description
flip-sale	Toggle public minting on/off
flip-burn	Toggle burning (phase upgrades) on/off
deposit-ft	Deposit SIP-010 tokens into the contract (prize pool)
withdraw-ft	Withdraw SIP-010 tokens from the contract
withdraw-stx	Withdraw STX from the contract

Player actions

Function	Description
claim-one	Mint 1 NFT
claim-five	Mint 5 NFTs
claim-ten	Mint 10 NFTs
claim-twenty-five	Mint 25 NFTs
burn-phase-1	Burn 5 Phase 1 NFTs → receive Phase 2 NFT
burn-phase-2	Burn 5 Phase 2 NFTs → receive higher-tier reward (mode-specific)

Read-only

Function	Description
sale-enabled	Check if public minting is active
burn-enabled	Check if burning is active

Internal (implementation detail)

Function	Description
claim	Single-mint helper used by batch functions
send-ft-to-winner	Distribute SIP-010 prize tokens under game-defined conditions

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How the encrypted layer works (high level)

The contracts handle ownership, transfers, minting, burning, and payouts.
The private payload is gated by ownership: only the current owner can access/decrypt it via a signed request.

Current model (v1 — hybrid):

• On-chain: NFT ownership + commitment hash + transfer/burn logic
• Off-chain (app layer): encrypted payload storage + owner-gated decryption
• Commitment hash prevents payload swaps (the app must match the on-chain commitment)

Roadmap (optional): We aim to reduce trust assumptions over time (e.g., more on-chain storage / stronger verification guarantees).
See SIP + docs for the evolving spec and security considerations.

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Development

Requirements: Clarinet (Hiro) — https://github.com/hirosystems/clarinet

# Run tests
clarinet test

# Check contracts
clarinet check

# Console (local devnet)
clarinet console

Project structure:

contracts/ # Clarity smart contracts settings/ # Clarinet deployment configs Clarinet.toml # Project manifest

License

GPL-3.0