BTX

BTX is a proof-of-work blockchain built on post-quantum cryptography at the consensus level. A fork of the Bitcoin Knots v29.2 node software, it removes elliptic curve cryptography entirely: every transaction signature uses ML-DSA-44 or SLH-DSA-128s, and ECDSA is not valid in consensus. The network targets a 90-second block time and a supply cap of 21,000,000 coins.

#Design

BTX inherits the UTXO accounting model, peer-to-peer networking, and most of the consensus machinery of Bitcoin Knots v29.2, a widely used Bitcoin node implementation. The node software is written in C++; a public source mirror is maintained at github.com/btxchain/btx, and protocol documentation is published at btx.dev.

The signature layer is the sharpest departure from upstream. Transactions are signed with ML-DSA-44, a lattice-based scheme standardized by NIST in FIPS 204, or with SLH-DSA-128s, a conservative hash-based scheme standardized in FIPS 205. Because ECDSA does not exist in BTX consensus, no output on the network carries the elliptic curve exposure analyzed in quantum threat to ECDSA.

#Outputs and addresses

Every BTX output uses a single output type called P2MR, a witness version 2 construction based on MAST (Merklized Alternative Script Trees) with leaf version 0xc2. Alternative spending scripts are committed in a Merkle tree, and only the branch actually used is revealed at spend time. Addresses are encoded in bech32m and begin with the prefix btx1z.

#Consensus parameters

The MatMul proof of work replaces Bitcoin's double SHA-256 with repeated matrix multiplication over a Mersenne finite field. Post-quantum signatures are substantially larger than the roughly 70-byte ECDSA signatures they replace, and the block size ceiling of roughly 24 MB reflects that.

#Script capabilities

OP_CTV (CHECKTEMPLATEVERIFY) and OP_CSFS (CHECKSIGFROMSTACK) are active from genesis, alongside the CLTV and CSV timelock opcodes inherited from Bitcoin. CTV lets an output commit to the exact template of the transaction that spends it, and CSFS lets a script verify a signature over arbitrary stack data. Together they enable covenant-style spending restrictions that on Bitcoin remain proposals rather than active consensus rules.

#Transaction relay and privacy

Transactions propagate with Dandelion++ relay in the style of BIP 156. A new transaction first travels along a randomized stem path of peers before being diffused to the whole network, which makes it harder for an observer to link a transaction to the IP address that originated it.

BTX launched with a shielded pool named SMILE, a lattice-based construction for confidential transfers. The pool is being sunset: consensus rules disable the creation of new shielded credits after block 125,000, leaving the transparent P2MR layer as the network's ongoing design.

#Network status and limitations

BTX is a young network, and its total hashrate is small compared to Bitcoin. On any small proof-of-work network the cost of acquiring a hashrate majority is lower, so deep reorganizations are a more realistic risk than on large, established chains. The node software includes an opt-in mitigation that parks deep reorganizations instead of following them automatically, trading automatic convergence for operator intervention in extreme cases.

Like other post-quantum blockchains, BTX shows that NIST's post-quantum signature standards can operate in a live blockchain. The practical security of the network, however, also depends on hashrate, node distribution, and software maturity, none of which are established at the scale of Bitcoin.

#Ecosystem

Software built on BTX includes the BZA1 artifact standard for on-chain collectibles, the qID identity system and the qID Connect connection layer, the PQ Wallet desktop wallet, the bonuz wallet mobile wallet, the BTXScan block explorer, and EVX, a private EVM-compatible layer 2. Collectible releases that use BZA1 are indexed at BTX drops.