# QMS Technology ### QUBO Problems QMS's initial PoUW implementation uses QUBO problems. Solving a QUBO is mathematically equivalent to finding the ground state of an Ising Hamiltonian, the lowest-energy configuration of the system. This is precisely the task that Quantum Annealing hardware and the Quantum Approximate Optimization Algorithm (QAOA) are designed to tackle. Because many practical problems in logistics and finance, including portfolio optimization and vehicle routing, can be formulated as QUBO instances, the QMS network can be rented to solve real commercial problems. The modular design of the PoUW implementation allows new problem types to be added as the network evolves. ### Security of PoUW A fundamental challenge for any PoUW system is preventing a party from submitting problems they have pre-solved, then mining exclusively with pre-computed answers. QMS's implementation closely follows Ofelimos (Fitzi et al., CRYPTO 2022), which addresses this through three mechanisms: * The solver must use a randomized algorithm (e.g., simulated annealing, tabu search, evolutionary algorithms), so its outputs are non-deterministic. * The randomness seed is derived from a hash of the parent block, making it unpredictable until the previous block is published. * The right to produce a block is determined by a lottery based on any valid solver output, not on solution quality. Pre-computation therefore gives no advantage in winning blocks or controlling the chain. QMS's PoUW design provides the same liveness and persistence guarantees as Bitcoin-style PoW—properties formally proven in peer-reviewed cryptography research (Fitzi et al., CRYPTO 2022). ### Integrating Quantum Miners The PoUW architecture creates two pathways for quantum hardware to participate in the network. The first is built into the incentive structure from the start. While block production rights are determined by a lottery unrelated to solution quality, client payments are distributed based on how good the solutions are. A miner that consistently finds higher-quality QUBO solutions earns a larger share of client payments. No protocol change is required: better computation is rewarded regardless of how it is achieved. This means that quantum hardware, including early prototypes, can join the network and earn competitive rewards as soon as it is capable of producing strong solutions, even if it only wins a modest share of blocks. The second is a longer-term research direction. The Ofelimos security framework relies on the miner's randomness being seeded by the parent block hash, a mechanism that does not directly extend to quantum computers, which are fundamentally random by nature. QMS is working with academic partners to develop an equivalent security framework that covers both quantum solvers and classical ones. ### Finalization Layer QMS runs a finalization layer alongside the main consensus protocol. Its role is simple: validators who stake tokens vote to mark certain blocks as final. Once a block is final, the chain will never roll it back. This adds a practical safety net while PoUW parameters are calibrated on a live network. It also protects the chain during its early growth. A new proof-of-work chain with relatively modest computational power is vulnerable to a 51% attack if a large external miner, such as a decommissioned Bitcoin mining operation, joins and seizes control. A centralized finalization layer prevents this at launch by ensuring that no single party can rewrite recent history, regardless of their share of mining power. As the network grows and token distribution broadens, the validator set opens up and the finalization layer decentralizes. Because finalization happens asynchronously, and finalizing any block automatically finalizes all its ancestors, the finalization layer processes blocks at its own pace without affecting block production or transactions per second. This also means that upgrading validators to PQ signatures will have no impact on chain throughput. ### Post-Quantum Security QMS's approach to the PQ security transition spans three layers: * Consensus layer: PoUW requires no digital signatures, making it quantum-resistant by design. * Execution and finalization layers: Initial versions use standard signatures for compatibility. PQ signature schemes will be introduced in subsequent updates, allowing users to opt in before it becomes mandatory network-wide. * Protecting dormant accounts: When non-upgraded accounts are eventually frozen, legitimate owners can recover their funds by providing a zero-knowledge proof that they know the seed from which their private key was derived. Quantum computers can compute a private key from a public key using Shor's algorithm, but cannot invert a cryptographic hash to recover the seed. This recovery path therefore remains secure even against a quantum adversary. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.qms.finance/qms-technology.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.