Project website and current release status: projectblackcoin.org
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.
- Quantum-safe signatures. ML-DSA-44 (FIPS 204) via liboqs as the consensus-verified spending path for quantum migration (witness v16) and quantum cold-staking (v14). Witness v15 is frozen and reserved for a future EUTXO design, but v30.1.1 provides no supported v15 funding or spending workflow because it has no quantum ownership authorization. Consensus rejects v15 funding and spending from Migration onward.
- A bounded, one-click migration. Gold Rush is followed by a scheduled
18-month Migration phase in which holders can move legacy elliptic-curve
coins into quantum-safe addresses with
migratetoquantum. Legacy coins remain spendable during Gold Rush, but ordinary quantum funding does not activate until Migration. Final Lockout then closes the legacy spending path. - 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. Demurrage activates automatically at the first Final block. Eligible quantum coins that then remain inactive for more than six months slowly decay. Decayed principal is permanently burned when spent and is never paid to a miner, staker, treasury, or reward pool. A timely direct/tiered-v16 liveness attestation, ordinary spend, or successful cold-stake refresh keeps the applicable activity clock current.
- Rich quantum staking. Tiered self-staking, cold staking with owner/staker key separation, operator bonds, a per-pool decentralization cap, and conditional owner-wallet redelegation.
- Advanced primitives. RGB client-side asset commitments plus inspection-only EUTXO commitment decoding and wallet metadata. Do not fund a witness-v15 address in v30.1.1; its creation and spend RPCs intentionally fail.
The mainnet lifecycle is height-authoritative. Median-time-past cannot advance, delay, or reverse a production phase transition. Durations below are estimates based on Blackcoin's 64-second target spacing; the listed heights are the consensus boundaries.
| Phase | Mainnet heights | Approximate duration | Legacy spend? | v14/v16 funding and spending? | Gold Rush? |
|---|---|---|---|---|---|
| Legacy | through 5,949,999 | - | Yes | No | No |
| Gold Rush | 5,950,000-6,192,999 | 180 days | Yes | No; shadow credits are locked | Yes |
| Migration | 6,193,000-6,921,999 | 540 days | Yes | Yes | No |
| Final Lockout | from 6,922,000 | permanent | No | Yes | No |
Witness v15 has no supported funding or spending workflow in any v30.1.1 phase. From Migration onward, consensus rejects both v15 outputs and v15 spends. The phase table's quantum column refers only to the authenticated v14 and v16 paths.
The 10,000 BLK Gold Rush whitelist snapshot is taken at height 5,945,000. Full schedule and constants are in the white paper.
Height 5,993,200 is also an operator upgrade boundary. It starts the new v30.1.1 canonical competing-claim rule (the QQP3, rank-v1 rule), not QQP4. v30.1.0 and v30.1.1 continue to accept the same Gold Rush base chain, but only v30.1.1 applies the emission-neutral competing-claim reimbursement rule and therefore derives different shadow recipients and balances from that height. Wallets, staking and mining nodes, explorers, and indexers that consume the shadow ledger must upgrade before the boundary. Do not reopen a wallet/datadir that has processed post-boundary v30.1.1 state in v30.1.0; use the cold pre-upgrade copy for rollback. Base-chain compatibility does not imply identical shadow state.
QQP4 exact-input proofs have a separate consensus activation. This release
leaves that activation disabled on mainnet (INT_MAX); a readiness bit or other
signalling state cannot enable it. A future QQP4 release must publish an
explicit activation height and include a declared, tested Q3 late-claim
transition and replay path before it is scheduled.
The wallet permits only one unresolved fee-paying QQSPROOF claim at a time.
If a claim leaves the local mempool, it remains quarantined and its input stays
reserved because another peer can retain and later confirm the transaction.
The miner pauses rather than creating an unsafe competing claim, and generic
abandontransaction refuses to release that input.
getpowmininginfo reports the unresolved, live, and quarantined wallet-authored
claim counts. An operator who chooses to resolve a quarantined claim can first
preview an exact-input, same-script conflict with
createshadowpowclaimresolution <claim_txid>. Signing requires a normally
unlocked wallet, dry_run=false, and explicit
acknowledge_fee_and_conflict_risk=true; the RPC still never broadcasts.
Review its fee and warning, then call sendrawtransaction separately only if
you accept the conflict risk. The resolution fee receives no shadow
reimbursement, peers retaining the original may reject the conflict, and
confirmation is not guaranteed. The input remains reserved until either the
original claim or the resolution actually confirms. After an operator
explicitly broadcasts the signed resolution and the wallet learns it, ordinary
wallet rebroadcast may continue across restart; that is downstream of the
separate broadcast decision and does not add new consent.
v30.1.1 uses authenticated auxiliary-state schema 12 and normalizes historical UTXO timestamps. An existing v30.1.0 datadir must not be used for staking or mining under v30.1.1 until it has completed one explicit chainstate rebuild. Back up every wallet, stop the old process completely, and run:
blackcoind -datadir=/path/to/data -networkactive=0 -staking=0 \
-reindex-chainstate -daemonwait-reindex-chainstate reconstructs state from local block files; it does not
retrieve block history that has already been pruned. The datadir must contain
the complete active-chain block data needed for the rebuild. If block files are
pruned or incomplete, set prune=0 and use a full -reindex so the missing
history can be downloaded and the block index and chainstate rebuilt. Do not
delete wallet files or available block files. v30.1.1 checks required block
availability before staging and leaves the existing chainstate intact if known
pruned history makes a chainstate-only rebuild impossible.
v30.1.1 supports archival prune=0 operation only. Startup rejects a
nonzero -prune value on mainnet, testnet, and signet because this Blackcoin
branch does not have an audited proof-of-stake pruning and recovery path.
Nonzero values remain available only on regtest for test coverage. Keep
complete active-chain block files for authenticated Quantum Quasar replay.
Before moving either source chainstate, the protected rebuild scans its stable directory topology and requires enough free space for at least the logical size of the existing chainstate plus a 50 MiB safety reserve. A failed scan or space check leaves the source in place without creating a rebuild journal.
The rebuilding process preserves the original chainstate in a journaled backup
and leaves that backup in place after reconstruction commits. Stop cleanly and
start once more without either reindex option so a separate process can verify
the replacement before retiring the backup. Do not request a full -reindex
between those two starts; v30.1.1 refuses that transition rather than risking
the preserved recovery point.
v30.1.1 does not claim power-loss-atomic directory renames on Windows. Keep a cold datadir copy, use stable power, and do not force-stop or power-cycle Windows during the rebuild or its verification restart. If startup reports a chainstate-rebuild journal or backup-topology error, preserve the entire datadir and restore the cold copy instead of deleting recovery files individually.
The base node, P2P, staking, mining, and consensus paths do not depend on the
optional full circulating-supply scan. Before requesting that diagnostic,
inspect getshadowresourceinfo. A scan is single-flight, reports progress, and
can be cooperatively stopped with abortcirculatingsupplyscan. Outside the
reviewed operating envelope, getcirculatingsupply requires explicit one-call
consent; that consent cannot bypass the absolute record/seek limits, integrity
floor, storage reserve, snapshot, overflow, shutdown, or cancellation checks.
Even a successful qualification is fixed-height and host-scoped, reports
universal_consensus_bound=false, and is not a universal chainstate bound.
After synchronization, record and compare the height, best-block hash, UTXO MuHash, and Gold Rush totals across a clean restart:
blackcoin-cli getblockchaininfo
blackcoin-cli gettxoutsetinfo muhash
blackcoin-cli getgoldrushstateAt or after the whitelist height, also require getgoldrushstate.replay_state
to report schema 12 with present, marker_valid, and valid_for_tip all
true. Keep the pre-upgrade wallet backup until the values and replay commitment
remain stable after a clean restart and a second offline chainstate rebuild.
On first run without -datadir or -conf, blackcoind and blackcoin-qt inspect the
default .blackcoin and legacy ~/.blackmore locations but never select wallet data
automatically. The GUI shows source, destination, backup/rollback behavior, and applicable
migrate or exit/manual choices. Headless startup fails closed before backup or import and
prints the exact one-shot -migratewallet=blackmore, -migratewallet=blackcoin, or
-migratewallet=none command. Remove that command-line option after the successful first
run. Blackmore import remains copy-first, converts blackmore.conf to blackcoin.conf, and
leaves the original intact. Migration failures abort startup rather than loading the wrong
wallet. Ensure there is enough free disk for the selected directory and verified backups.
Important: ML-DSA quantum keys are not derived from your HD seed. Back up your wallet again after creating any quantum address (migration, staking, operator, or cold-stake), or a restore from an older backup will not recover those funds.
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 -j8For local development only, an exact-version host liboqs can be used instead:
./autogen.sh
./configure --with-system-liboqs
make -j8The primary binaries are src/blackcoind, src/blackcoin-cli, src/blackcoin-wallet, and
src/qt/blackcoin-qt.
# 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.pyBlackcoin 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. Mainnet phase membership is height-authoritative. The whitelist height, Gold Rush and Migration boundaries, and Final Lockout height are consensus rules, so every node that wishes to remain on the same chain must use identical height values. The retained timestamp anchors are nominal forecasts, not mainnet phase boundaries.
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.
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