Abstract
HashCore ($HASH) is a proof-of-work ERC-20 token on Robinhood Chain. Unlike tokens that are minted once and distributed, every $HASH is earned by solving a real SHA-256 proof-of-work challenge in the browser via WebGPU, then verified on-chain by a smart contract. There is no premine, no team allocation, and no insider mint button. The only way to obtain $HASH is to mine it with real compute.
1 · Why Proof-of-Work on Robinhood Chain
Robinhood Chain is an Ethereum Layer 2 (Arbitrum Orbit) with a single sequencer and no native consensus token. It also lacks a native on-chain randomness source (VRF). Proof-of-work fills that gap: it turns raw compute into a verifiable, fair source of randomness and minting rights. HashCore brings the spirit of Bitcoin's proof-of-work to a modern L2 — but instead of ASICs and mining farms, the work runs on the GPUs already inside every user's browser.
2 · The Proof-of-Work
Each attempt hashes a 60-byte message:
sha256( challenge(32) ‖ miner(20) ‖ nonce(8) ) < target
- challenge — a 32-byte value held by the contract, rotatable by the owner to prevent precomputation.
- miner — the miner's 20-byte address, binding the proof to a specific account.
- nonce — a 64-bit value the miner increments until the hash clears the target.
- target — derived from the difficulty; a lower target means harder mining.
The miner searches for a nonce that drives the hash below the target. The contract recomputes the same SHA-256 (via the 0x02 precompile) and mints fresh $HASH only if it verifies. A nonce can never be reused: every (challenge, miner, nonce) is marked as used on-chain.
3 · Token Economics
- Total supply: 21,000,000 HASH — a deliberate homage to Bitcoin.
- Initial reward: 50 HASH per mint.
- Halving: every 210,000 mints, the reward halves.
- Difficulty: starts at 36 bits and rises by 1 bit every 100,000 mints, keeping block times roughly stable as hashrate grows.
- No premine, no team allocation, no insider mint. Every token enters circulation through mining.
4 · Mining
Mining runs entirely in the browser. The WebGPU API compiles a WGSL SHA-256 kernel that executes on the user's GPU, searching millions of nonces per second. A mid-range GPU (RTX 3060 Ti) benchmarks at ~1.3 GH/s, clearing the initial difficulty in about a minute. When a valid nonce is found, the browser locally re-verifies the hash with WebCrypto, then sends a single mint transaction for on-chain finalization.
5 · Security & Fairness
- Replay protection: each (challenge, miner, nonce) is single-use.
- Precomputation resistance: the challenge can be rotated, invalidating any offline work.
- On-chain verification: the contract, not the client, decides whether a proof is valid.
- Binding: the miner's address is part of the hash, so a proof cannot be replayed by another account.
6 · Roadmap
- Phase 1 — Genesis: contract deployment, browser mining, wallet integration.
- Phase 2 — Community: public leaderboard, difficulty tuning, multi-wallet support.
- Phase 3 — Market: liquidity and trading for $HASH.
7 · Disclaimer
HashCore is an experimental proof-of-work token. $HASH has no intrinsic value and is not an investment, security, or financial instrument. Mining consumes electricity and GPU resources. Nothing here is financial advice.
