Blackcoin, Quantum Quasar (Protocol V4)

Blackcoin is one of the original pure Proof-of-Stake cryptocurrencies (launched 2014). Quantum Quasar (Protocol V4) is its post-quantum, participation-first upgrade: it adds NIST-standardized quantum-safe signatures, a deterministic migration away from quantum-vulnerable legacy outputs, and a set of reward and liveness mechanics designed to turn passive holding into active network security, while rewarding HODLers in full for helping secure the chain.

New here? Read the Quantum Quasar White Paper (PDF / Markdown) for the complete protocol specification with worked examples, exact consensus constants, and a community playbook. Legacy operators should read the Transition Guide before upgrading. See the Changelog for what shipped in each release.

What Quantum Quasar delivers

• Quantum-safe signatures. ML-DSA-44 (FIPS 204) via liboqs as a consensus-verified spending path, with new SegWit witness versions for quantum migration (v16), EUTXO smart contracts (v15), and quantum cold-staking (v14).
• A bounded, one-click migration. A generous 24-month window to move legacy elliptic-curve coins into quantum-safe addresses with migratetoquantum, after which the legacy spending path closes, converting a permanent, network-wide vulnerability into a finite, individually-avoidable one.
• The Gold Rush. A 180-day bonus-emission epoch (up to 51,437,700 BLK) paid to holders through staking and mining, split 50/50 between native PoS and a light, CPU-friendly Argon2id PoW lane.
• Liveness demurrage. Directly-held quantum coins that are abandoned for more than six months slowly decay, with the reclaimed value flowing to active stakers, while any holder who participates even minimally (one automatic attestation, or a single cold-stake delegation) keeps 100% forever.
• Rich quantum staking. Tiered self-staking, cold staking with owner/staker key separation, operator bonds, a per-pool decentralization cap, and autonomous redelegation.
• Advanced primitives. EUTXO smart-contract outputs and RGB client-side asset commitments.

The V4 timeline (mainnet)

Protocol V4 activates at a fixed time (2026-07-12, ~block 5,950,000) and moves through four phases:

Phase	Starts	Duration	Legacy spend?	Quantum spend?	Gold Rush?
Legacy	(before V4)	—	✅	❌	❌
Gold Rush	V4	180 days	✅	fundable	✅
Migration	V4 + 180 d	540 days	✅	✅	❌
Final Lockout	V4 + 720 d	permanent	❌	✅	❌

The 10,000 BLK Gold Rush whitelist snapshot is taken at height 5,945,000. Full schedule and constants are in the white paper.

First run and data migration

On first run without -datadir or -conf, blackcoind and blackcoin-qt look for a legacy ~/.blackmore data directory. If it is the only legacy data directory, the node copies it to ~/.blackcoin, converts blackmore.conf to blackcoin.conf, leaves the original intact, and writes a migration marker. If both .blackcoin and .blackmore exist, the GUI prompts and headless startup safely keeps .blackcoin unless -migratewallet=blackmore is supplied. Migration failures abort startup rather than loading the wrong wallet. Ensure there is enough free disk for a full copy of the selected legacy directory and its backup.

Important: ML-DSA quantum keys are not derived from your HD seed. Back up your wallet again after creating any quantum address (migration, staking, or cold-stake), or a restore from an older backup will not recover those funds.

Build

Protocol V4 consensus requires liboqs 0.15.0 for ML-DSA quantum signatures. Release builds must use the pinned dependency tree:

make -C depends
./autogen.sh
./configure --prefix="$PWD/depends/$(./depends/config.guess)"
make -j8

For local development only, an exact-version host liboqs can be used instead:

./autogen.sh
./configure --with-system-liboqs
make -j8

The primary binaries are src/blackcoind, src/blackcoin-cli, src/blackcoin-wallet, and src/qt/blackcoin-qt.

Test

# focused Blackcoin / Quantum Quasar checks
./src/test/test_blackcoin --run_test=shadow_tests,blackcoin_tests --catch_system_errors=no
python3 test/functional/feature_blackcoin_phase.py
python3 test/functional/rpc_goldrushinfo.py
python3 test/functional/rpc_rgb.py

# full functional suite
python3 test/functional/test_runner.py

Relationship to Blackcoin More

Blackcoin Quantum Quasar is a fork of, and an advancement of, CoinBlack/blackcoin-more. It targets the same Blackcoin network, Quantum Quasar is a consensus upgrade for the existing chain, not a new coin. All code here is MIT-licensed and free to be re-incorporated upstream; contributions in either direction are welcome. Because the V4 activation time, whitelist height, Gold Rush schedule, and migration deadline are consensus rules, any node that wishes to remain on the same chain must run identical values.

Development notes

This repository still contains legacy Blackcoin compatibility names where they are protocol, URI, historical, migration, or test-framework compatible. New user-facing code should use the Blackcoin daemon, CLI, wallet, and configuration names.

License

Blackcoin is released under the MIT license. See COPYING for details.

Copyright (C) 2024-2026 Quantum Quasar Developers Copyright (C) 2009-2026 Blackcoin Core Developers Copyright (C) 2018-2026 Blackcoin More Developers Copyright (C) 2014-2026 Blackcoin Developers