In 2025, the concept of a quantum internet—an interconnected network capable of transmitting
quantum information (qubits)—has moved from theoretical research into early-stage pilot deployments.
Driven by advances in quantum hardware, photon-based quantum communication channels, and the
urgent need for provably secure data transmission, multiple national research programs and private
consortia have launched demonstration projects. This document provides a comprehensive overview of
the current state of quantum internet development as of mid-2025, including hardware progress,
network architectures, international collaborations, cryptographic implications, and near-term roadmaps
toward broader adoption.
To begin, the foundational principle of a quantum internet rests on the ability to generate, distribute,
and manipulate entangled quantum states between distant nodes. Entanglement enables phenomena
such as quantum teleportation, superdense coding, and unconditionally secure key distribution
(quantum key distribution, or QKD). Early experiments dating back to 2015 demonstrated entanglement
distribution over tens of kilometers of optical fiber; by 2020, satellite-based QKD was achieved, most
notably by China’s Micius satellite, which performed entanglement-based key exchange between ground
stations separated by over 1 200 km. In 2024 and 2025, building on Micius’s successes, researchers have
started to stitch together small-scale quantum networks on different continents.
In China, the Quantum Experiments at Space Scale (QUESS) initiative has continued to refine satellite-to-
ground QKD. In January 2025, a newly launched quantum communication satellite—often referred to as
Micius-2—demonstrated entanglement distribution between Beijing and Urumqi ground stations over a
free-space distance of approximately 2 500 km. This record-setting link transmitted entangled photon
pairs from low Earth orbit (LEO) and achieved a Bell test violation over that distance, confirming
entanglement fidelity above 80 percent even under atmospheric turbulence. Simultaneously, China
expanded its terrestrial quantum backbone: by March 2025, the existing 4 000 km Beijing–Shanghai
Quantum Backbone Network was extended to Wuhan and Chengdu, resulting in a total of over 6 000 km
of dedicated dark-fiber quantum channels. These fiber links primarily use polarization-encoded qubits at
telecom wavelengths (1 550 nm) with ultralow-loss splices and cryogenically cooled superconducting
nanowire single-photon detectors (SNSPDs) at each node to minimize quantum bit error rates (QBER) to
below 1 percent. The network now interconnects six major universities, two financial hubs, and three
government research laboratories, enabling real-time QKD for secure communications among Beijing,
Shanghai, Wuhan, Chengdu, Shenzhen, and Xi’an.
In the United States, the Department of Energy (DOE) National Quantum Internet Blueprint—initially
released in late 2023—has guided federal funding toward building a coast-to-coast research testbed. In
late 2024, the DOE awarded million to a consortium led by Los Alamos National Laboratory (LANL),
Fermilab, and the University of Chicago to design and construct a quantum backbone spanning from
Chicago to Los Angeles. By May 2025, the first 100 km link between Argonne National Lab (near Chicago)
and a newly built quantum node at Northwestern University was activated. This link uses time-bin
encoding for qubits, multiplexing classical and quantum signals over the same fiber, and employs
entanglement swapping at a Fermilab relay station in Aurora, IL. The pilot network currently supports
intercity QKD at rates up to 1 Mbps for symmetric key generation, which is sufficient for real-time
encryption of video streams and secure command-and-control signaling. In parallel, the DOE Quantum
Internet Blueprint calls for the development of quantum memory nodes capable of storing entangled
states for periods exceeding one second—crucial for long-distance entanglement distribution via
quantum repeaters. As of June 2025, LANL’s experimental quantum repeater prototype uses rare-earth–
doped crystal memories operating at 1.5 Kelvin to achieve storage times of up to 2 seconds with a
retrieval fidelity of 90 percent; several iterations are planned before field deployment in late 2026.
In Europe, the Quantum Flagship program’s “Quantum Internet Alliance” (QIA) has coordinated efforts
among twenty universities and research centers across Germany, France, Italy, the Netherlands, and
Switzerland. A major milestone occurred in February 2025, when the NetherQuantum consortium
completed the construction of a 150 km fiber-based quantum link between Delft and The Hague in the
Netherlands. This link uses advanced wavelength-division multiplexing (WDM) to integrate two 10 Gbps
classical channels alongside a 10 MHz entangled-photon-pair channel without cross-talk, demonstrating
a coexisting classical-quantum network architecture. Moreover, QIA partners in Germany have deployed
a 50- km testbed connecting Berlin’s Humboldt University and Potsdam University, integrating
superconducting transmon-qubit nodes that can generate and store GHZ (Greenberger–Horne–Zeilinger)
states among three separate processors. This multi-node architecture is the first step toward
implementing distributed quantum algorithms—such as blind quantum computation—over
metropolitan-scale distances. The European Commission has pledged an additional €300 million over the
next five years to extend these national testbeds into an interconnected “European Quantum Backbone”
by 2030.
Complementing government and academic initiatives, several private-sector consortia have emerged.
Quantum Xchange (QX), a U.S.–based startup founded in 2021, operates a coast-to-coast trusted-node
QKD network that now connects New York, Boston, Washington D.C., and San Francisco via dark fiber. In
May 2025, QX announced the integration of a hybrid key-distribution scheme combining satellite QKD
from the Micius-2 downlink and terrestrial fiber QKD, allowing clients to choose the optimal path based
on weather conditions and network congestion. This hybrid approach increases overall uptime to over 99
percent annually, compared to 80 percent for satellite-only links that suffer from cloud cover. The QX
network currently offers subscription-based QKD services to major banks, financial exchanges, and
defense contractors, charging approximately .10 per bit of secure key material—with volume discounts
for high-throughput users. Meanwhile, Toshiba Europe launched a “Quantum Network as a Service”
(QNaaS) model in March 2025, installing QKD equipment at telecom carrier data centers in London and
Frankfurt. Their solution uses continuous-variable QKD (CV-QKD) at 1 300 nm that can operate alongside
standard multi-mode fibers, enabling retrofit deployment without dedicated dark fibers. Early customers
include two multinational banks and one cloud provider, which use the service to secure data-center–to–
data-center VPN tunnels.
On the hardware front, progress in quantum transducers—devices that convert microwave photons
(used by superconducting qubits) to telecom-wavelength photons—has been pivotal. At Caltech, a team
led by Dr. Sarah Carter published in January 2025 a paper describing an electro-optomechanical
transducer that achieves 50 percent internal conversion efficiency at room temperature, with a
bandwidth of 10 MHz and added noise below one photon. In parallel, Oxford University researchers
demonstrated a piezoelectric-based transducer combining lithium niobate and silicon photonics,
achieving 60 percent conversion efficiency at 10 GHz with less than 0.5 dB insertion loss. These advances
are crucial for enabling long-distance entanglement distribution among superconducting-qubit
processors, which operate at microwave frequencies (5–10 GHz) and cannot directly interface with
optical fiber. Field‐qualified versions of these transducers are slated for deployment in mid ‐2026,
potentially enabling a hybrid quantum network connecting superconducting quantum computers in
Boston, Boulder, and Berkeley.
From a cryptographic standpoint, most commercial use cases currently focus on point-to-point QKD for
key distribution. However, as quantum networks grow, broader applications such as quantum
teleportation, distributed quantum sensing, and secure multi-party computation become feasible. In
November 2024, researchers at the University of Toronto demonstrated entanglement-based blind
quantum computation over a 100 km metropolitan link—allowing a client with minimal quantum
hardware to outsource a quantum computation to a remote quantum server without revealing the input
data. In March 2025, a group at ETH Zurich performed distributed quantum metrology by entangling
optical phonon modes across two labs separated by 80 km, achieving a sensitivity improvement of 30
percent over classical interferometry for phase estimation. These early experiments hint at future
quantum internet applications in fields like distributed sensing for gravitational-wave detection, secure
cloud-based quantum computing, and networked quantum clocks for precision timekeeping.
Nevertheless, several challenges remain on the path to a fully functional quantum internet. First, photon
loss over distance is significant: even with ultralow-loss fiber (~0.15 dB/km at 1 550 nm), entanglement
distribution beyond 500 km requires quantum repeaters to perform entanglement swapping,
purification, and storage. While prototype quantum repeater nodes exist in laboratories, engineering
them into robust, field‐deployable units with high throughput remains an open engineering problem.
Second, end-to-end quantum network management—routing entangled pairs among multiple nodes
with asynchronous requests—demands new protocols. The Quantum Internet Research Group (QIRG),
established in mid-2024, has drafted the first “Quantum Routing and Control” (QRC) protocol, which
specifies how to negotiate entanglement requests, allocate memory resources at each node, and
perform error management. As of June 2025, QIRG is working with the Internet Engineering Task Force
(IETF) to standardize QRC by 2026. Third, integration with existing telecom infrastructure poses
compatibility issues: classical error-correction and packet-routing methods cannot directly apply to
quantum payloads, which are inherently delicate and cannot be amplified without destroying the
quantum state. Researchers are exploring “quantum-aware” optical switches that can selectively route
entangled photons without conversion to electrical signals, but these are still in prototype form.
International collaboration is a key enabler. In May 2025, the U.S. National Institute of Standards and
Technology (NIST), China’s CAS Institute of Quantum Electronics, Europe’s QUARTZ project, and Japan’s
National Institute of Information and Communications Technology (NICT) signed a memorandum of
understanding (MoU) to share best practices, align key quantum network standards (wavelength,
entanglement fidelity metrics, error-correction thresholds), and coordinate satellite-based QKD launch
windows to facilitate intercontinental entanglement experiments. One planned experiment involves
using the next-generation QKD satellite (launched by ESA in late 2025) to distribute entangled photons to
ground stations in Paris, Tokyo, and San Francisco, effectively linking Europe, Asia, and North America via
a global quantum network. These intercontinental tests aim to validate quantum teleportation of
atomic-ensemble quantum memories over distances of 10 000 km by 2027.
Governments are also enacting policy frameworks to promote secure quantum networks. In February
2025, the U.S. Senate passed the Quantum Network Information Act, appropriating million over five
years to support research into scalable quantum repeaters, quantum memory nodes, and integrated
quantum photonic chips. Additionally, the Act creates a “Quantum Network Innovation Center” (QNIC)
within the National Science Foundation (NSF) to fund university–industry partnerships for prototyping
components and testing architectures. Similarly, the European Commission’s Digital Europe Programme
earmarked €250 million for the period 2025–2028 to support commercial QKD service providers and to
subsidize equipping critical infrastructure—such as national energy grids and military command centers
—with quantum-secure communication links.
Security and regulatory considerations are paramount as quantum networks become viable for critical
infrastructure. Once large-scale quantum computers become available—which IBM and Google both
project by 2026—classical encryption algorithms like RSA and ECC will be breakable. Governments are
therefore incentivizing the transition to quantum-safe cryptography. In mid-2024, NIST selected
CRYSTALS-Kyber and CRYSTALS-Dilithium as standard post-quantum cryptographic algorithms; by early
2025, all U.S. federal agencies were mandated to begin migrating to these algorithms for at-rest and in-
transit data. However, quantum-secured key distribution is seen as a complementary layer: organizations
can distribute quantum keys to bootstrap session keys, which then protect data using post-quantum
ciphers. Financial regulators in Europe and Asia have issued guidance requiring banks and trading venues
to demo a quantum-safe key management system by 2026 to continue offering cross-border payment
services.
Looking ahead, roadmaps for the quantum internet envision three phases:
1. **Phase 1 (2025–2027)**: Metropolitan quantum networks with trusted nodes linking universities,
research labs, and large enterprises within a single city or region. This includes pilot QKD networks in
Singapore (launched April 2025), Zurich, Ottawa, and Singapore’s Greater Southeast Asia Digital
Innovation Network (G-SADIN). Use cases focus on secure transmission of top-secret governmental data,
intellectual property protection for pharmaceutical R&D, and blockchain-anchored timestamping.
2. **Phase 2 (2027–2030)**: National-scale quantum backbones connecting multiple metro networks via
trusted-node relay stations or early-generation quantum repeaters. Planned deployments include the
U.S. QNCet (Quantum National Communications network) linking Washington D.C., Boston, Chicago, Los
Angeles, and Seattle; China’s National Quantum Network (NQN) spanning Beijing, Shanghai, Chengdu,
and Guangzhou; and Europe’s Quantum Backbone linking London, Paris, Berlin, Madrid, and Rome.
Technical goals include deploying second-generation quantum repeaters capable of error-corrected
entanglement distribution with storage times exceeding 10 seconds.
3. **Phase 3 (2030 and beyond)**: Global quantum internet utilizing satellite constellations, fully
operational quantum repeaters, and interoperable network standards. This global network would enable
real-time quantum teleportation of arbitrary qubit states among continents, secure distributed quantum
computing, and unconditionally secure telemedicine links among hospitals worldwide.
In conclusion, the year 2025 marks a pivotal inflection point for quantum internet research and
deployment. Advances in fiber-based QKD backbones, satellite entanglement links, quantum repeater
prototypes, and transducer technologies have collectively lowered the barrier to building operational
quantum networks. Governments are investing heavily in national and transnational initiatives, private
consortia are offering commercial QKD services, and standardization efforts are gaining momentum
through organizations like QIRG and IETF. While significant engineering challenges remain—especially
around scalable quantum repeaters, network management protocols, and integrating quantum
hardware with existing telecom infrastructure—the near-term roadmaps for metropolitan and national
quantum backbones appear feasible within the next two to three years. By 2030, the foundations laid in
2025 should enable a fully operational quantum internet, ushering in an era of unprecedented network
security, distributed quantum computing, and new quantum applications unthinkable in the classical
paradigm.
