# Whitepaper

SQRL: The Secure Quantum Reliable Ledger. A deterministic, Bitcoin-anchored settlement network for banking infrastructure. Version 4, November 2026, by Paul Dando and Ashif Asharaph.

> Part of the SQRL documentation, section "Protocol".
> Rendered page: https://docs.sqrl.tech/protocol/resources/whitepaper

(/downloads/sqrl-whitepaper.pdf)

The whitepaper specifies the network as it is being deployed: permissioned execution and governance above a permissionless settlement layer. It covers:

* **Network architecture**: the canonical ledger and its validator seats, banking subnets, cross-subnet routing, and supervisor observer nodes.
* **The execution substrate**: SCL, the compiler, the VM and the node, per-call anchoring, two-phase validation, state roots, reorg handling and partitioned state.
* **Payments and cross-border settlement**: issuance of stablecoins and deposit tokens, assets over Lightning, partner hubs with multi-asset channels and in-flight FX, and batch settlement.
* **Privacy** for banking subnets, in three phases.
* **Post-quantum security**: hash-based integrity, the NIST standards adopted, and the Bitcoin authorisation path.
* **Network economics**: XRB's mandatory fee path, subnet anchoring rent, settlement fees, capacity licences and front-loaded validator emissions.