QSIMPLUS

The problem

Building a quantum key distribution (QKD) experiment requires expensive optical parts, and access to test benches can take six months or more, DealSite reported in January 2024. Photon-level effects are hard to observe, which makes debugging slow and risky for labs, carriers and integrators. Once hardware is installed, tuning the post-processing that turns raw signals into keys takes weeks of expert work, according to the company.

The solution

QSIMPLUS sells a software and hardware stack: QSIMpro, a graphical simulator for quantum cryptography links; QSIMpro-LAN, operating software for quantum local area networks; QSIMunit, miniaturized hardware modules for fiber, free-space and satellite QKD, including the QSIMunit-SC signal generator; and QSIMpost-Opt, an AI library that automates QKD post-processing. The company is also developing an ultra-small dedicated chip and entangled photon sources.

How it works

1. In QSIMpro, users drag blocks standing for the transmitter, channel and receiver, then model the photon path for a protocol such as BB84.
2. They set experimental parameters (phase modulation, noise, losses) and the software plots computed results in real time, so errors surface before any component is bought.
3. In the field, QSIMunit modules generate and process the signals of a fiber or free-space QKD link.
4. QSIMpro-LAN runs an indoor quantum LAN and relies on Mobile Quantum Communication Nodes (MQCNs) to keep links up despite physical obstacles.
5. QSIMpost-Opt plugs into existing QKD hardware, learns its behavior in real time and uses machine learning to tune decoy ratios, detector noise thresholds and protocol settings for the longest secure key.

Value proposition

Test an architecture virtually before committing optical hardware, cutting experimentation cost and time. For QSIMpost-Opt, the company claims a 75% cut in development time and cost, with configuration data kept in-house rather than shared with outside consultants.

Technology edge

QSIMPLUS spans the whole chain, from design simulation to compact hardware and operating software. Its simulator visualizes each step of the link, which investors cited as a way to trace why an experiment failed (DealSite, January 2024). No hardware performance figures (key rate, reach) have been published.

Business model

B2B: software sales or licenses (simulation, network operation, post-processing), QKD hardware modules, and quantum information training. No public pricing.

Market

MarketsandMarkets (2024 estimate) sizes the global QKD market at about $0.48 billion in 2024, rising to $2.63 billion by 2030, roughly 32.6% annual growth. Target segments: R&D and teaching tools, secure enterprise and defense networks, and tuning of installed QKD equipment.

Competitors and alternatives

ID Quantique, which has a Seoul office, cites an 800 km nationwide network in South Korea and nearly 300 patents and applications; IonQ announced its acquisition in February 2025 alongside a strategic partnership with SK Telecom. Aliro Quantum offers a quantum network simulator and orchestrator supporting more than 50 devices, including Qunnect and Cisco hardware (September 2025). Toshiba is among the main QKD system vendors listed by MarketsandMarkets. QSIMPLUS sits further upstream, in design and tuning, with hardware that is still thinly documented.

Use cases

• A university lab simulates a BB84 link in QSIMpro to validate an optical setup before buying parts.
• A public research institute such as KISTI, which signed an MOU with QSIMPLUS covering transfer of its quantum key management system (QKMS) technology and joint R&D, builds these components into its work.
• A bank or defense agency runs an indoor quantum LAN managed by QSIMpro-LAN.
• A QKD equipment maker plugs QSIMpost-Opt into its systems to calibrate each installation automatically.

Traction and proof points

CES Innovation Awards Honoree four years running: 2023 (QSIMpro), 2024 (QSIMpro-LAN, Cybersecurity), 2025 (QSIMunit-SC) and 2026 (QSIMpost-Opt, Artificial Intelligence). Bronze at the 2023 Edison Awards. MOU with KISTI (date not given by the source). Selected for TIPS (the first quantum deep tech company in the program, per DealSite), Super-Gap Startup 1000+ (May 2023) and KODIT First Penguin (June 2024). Supported by Gyeonggi CCEI's Pangyo Startup Zone. Exhibited at CES from 2023 to 2026 (Eureka Park in 2023 and 2024, Hall D booth 36511 in 2026), at MWC Barcelona (4YFN) and at Quantum Korea 2025 (June 2025). No paying customer has been named publicly.

What remains to be proven

No paying customer or live deployment is on record, including with Korean carriers, and no hardware metrics (key rate, distance, error rate) have been released. The 75% saving claimed for QSIMpost-Opt is the company's own figure. Against ID Quantique, now backed by IonQ and SK Telecom, a team of at most about fifty people still has to show it can ship hardware at scale.