What Qanum is
What is Qanum?
Qanum is a post-quantum layer-1 monetary base: a UTXO ledger secured by proof-of-work, with seven native spending templates and post-quantum signatures from genesis. Its reference implementation, qanum-core, is a Rust full node (qanumd and qanum-cli) released under the MIT or Apache-2.0 license.
What are the block time and the monetary policy?
The target block time is 75 seconds. The block subsidy starts at 8 QAN and decreases by 10 % every annual epoch (420,480 blocks) down to a permanent tail of 0.2 QAN per block. There is no hard cap: supply is about 32.9 million QAN when the tail is reached (epoch 36), and the tail then adds about 84,096 QAN per year. 1 QAN = 100,000,000 jomas.
Does Qanum have smart contracts?
Not a general-purpose virtual machine. The base layer has seven native spending templates: single key, main key with a delayed recovery path, multisig (up to 16 keys), HTLC, vault, pending vault and burn. Scaling, advanced privacy and richer execution belong to higher layers.
How does Qanum help with self-custody?
Self-custody tools are part of the consensus rules, not wallet conventions: vaults with a delay on the hot key and immediate recovery with the cold key, main keys with a delayed recovery path, and threshold multisig (up to 16 keys) in which each cosigner signs offline on their own machine.
Security
Which post-quantum signatures does Qanum use?
NIST level 5 from the testnet genesis: ML-DSA-87 (FIPS 204) as the signing suite and SLH-DSA-SHAKE-256s (FIPS 205) for cold recovery, both verified with liboqs. At startup the node runs a known-answer self-test of every signature suite and refuses to start if it fails.
Is the peer-to-peer network post-quantum too?
Yes. Every peer connection runs a hybrid Noise handshake (X25519 + ML-KEM-1024, ChaCha20-Poly1305) authenticated by an ML-DSA-87 node identity, pinned on first use. There is no plain-text P2P on any network.
Is Qanum's proof of work quantum-resistant?
No, and no proof of work is, with any hash function. Grover’s algorithm gives a quadratic speed-up in the nonce search, for SHA3-256 exactly as for SHA-256. Post-quantum signatures protect spending, not mining. The per-block ASERT difficulty adjustment absorbs jumps in hash power within hours; the whitepaper (section 9.9) states the limits.
How do I protect and back up my wallet?
Encrypt it with encryptwallet <passphrase> (Argon2id) and make copies with backupwallet <destination>. Keep backups on encrypted media, never on a shared or networked machine, and rehearse a restore on regtest before you rely on it. The user guide has the details.
Has Qanum been audited?
Not yet. The pre-release reviews are internal, not independent audits. An external security audit is a condition for mainnet; the roadmap tracks its status.
How do I report a vulnerability?
Write to security@qanum.org, encrypted with PGP key 8013 E1BF F91C A30E E6A5 F273 01D9 6226 80BA FCA9 if you can. Please do not open a public issue before a fix is released. Details are in the security policy.
Nodes and storage
How do I run a node?
qanum-core is distributed as source code and built with Cargo on 64-bit platforms (x86_64 and aarch64); there are no pre-built binaries. The download page has the requirements, the build steps and how to verify a release.
Can a phone run a full node?
Yes. The qanum-embed library runs a full Qanum node inside a mobile app: one call starts it, it stops in about a second, and it syncs, mines and manages wallets. With the optional snapshot bootstrap, a phone reaches the tip of the chain in seconds through the same verified path as qanumd.
Are there light clients?
A node can build compact block filters (-blockfilterindex=1, off by default) and serve them to light wallets, which can then find their transactions without downloading every block. The filters also work on pruned nodes.
Can a new node sync without downloading the whole history?
Yes. A fresh node can start from a UTXO snapshot served by its peers (-snapshotibd=1) and then sync only the blocks after it. The snapshot is verified, not trusted: it carries the full header chain, and the node recomputes the commitment to the UTXO set (utxo_root) that every block header records. Before installing it, the tip must reach the network’s minimum chain work and be confirmed by an independent peer. The older block bodies can be fetched in the background (-backfillbodies=1), and if any check fails the node falls back to a full sync automatically.
Can I run a node with little disk space?
Yes. With -prune=1 the node keeps only the most recent blocks in full (2,000 by default, about 42 hours; minimum 288) and deletes older blocks and their undo data. It still validates every block and keeps the full UTXO set, so balances stay complete; block headers take about 127 MB per year. Wallet history only covers the blocks still on disk. Another mode, -auth-prune-depth, drops only old signatures and keeps blocks, undo data and indexes.
What is the difference between a snapshot and pruning?
They solve different problems. A snapshot decides how a new node starts: instead of downloading and checking every past block first, it installs a verified copy of the UTXO set and syncs from there. Pruning decides what a node keeps on disk afterwards: it deletes old blocks and keeps only the most recent ones. One saves time at the start, the other saves disk space for as long as the node runs.
Can I combine a snapshot and pruning?
Yes. Start a fresh node with -snapshotibd=1 -prune=1: it boots from a verified snapshot and then keeps only the most recent blocks. This is the lightest way to run a node that still validates every new block. The trade-off is that it cannot give old blocks or snapshots to other nodes; archive nodes do that.
Which setup suits my device?
Phone: an app with the qanum-embed library and the snapshot bootstrap, the recommended setting for mobile apps; on testnet a snapshot of about 12 MB was installed in about 25 seconds. Pruning is optional. Raspberry Pi or small home computer: qanumd with -prune=1, a 64-bit operating system and an SSD rather than an SD card; a Raspberry Pi 4 is the verified reference board. Desktop or server that helps the network: no pruning, so it can serve full history and snapshots to new nodes. Explorer or service that looks up transactions: no -prune, with -txindex; -auth-prune-depth saves space and keeps the indexes.
Is a node started from a snapshot as secure as one synced from the beginning?
From the snapshot onwards it checks every block exactly like any other node. For the history before it, it does not replay the old transactions: it checks that the UTXO set matches the commitment recorded in a block header backed by proof of work, that the chain reaches the network’s minimum chain work and that an independent peer confirms it. One limit is inherent to any snapshot: the node cannot reorganize below the snapshot height. If the network ever followed such a fork, the node says so in its log and must be resynced.
Can a pruned or snapshot node help the network?
Yes. It validates and relays new blocks and transactions like any node. What it cannot do is hand old blocks or snapshots to new nodes, so it announces itself only as a normal network node. Nodes with the full history on disk announce themselves as archive nodes and serve both.
Can I turn a pruned node back into a full node?
Not in place: deleted blocks do not come back, and a pruned datadir cannot be reindexed from disk. To have the full history again, sync a new datadir without -prune.
Can I use a transaction index on a pruned node?
No. -prune cannot be combined with -txindex or -addressindex, and the node refuses to start if you try. If you need the indexes with less disk, use -auth-prune-depth, which drops only old signatures and keeps the indexes. Compact block filters (-blockfilterindex=1) work with both modes.
Testnet
Is Qanum live? Is there a mainnet?
Qanum runs a public testnet since release v0.9.0 (17 October 2026). No mainnet genesis exists: mainnet launches only after an external security audit. Testnet coins (tQAN) have no value.
How do I get testnet coins?
Use the faucet with a testnet address (it starts with tqn1). Transactions and blocks can be followed in the testnet explorer.
Can I mine on the testnet?
Yes. qanumd has a built-in CPU miner: start it with qanumd -testnet -gen=1 --reward-address=tqn1... (an address from getnewaddress), or switch it on and off with qanum-cli -testnet setgenerate 1 and setgenerate 0. External miners can use getblocktemplate and submitblock. Testnet coins have no value.