Company lists · Data refreshed September 2026

Top 25 Quantum computing security companies based in the United States

RevenueBase identified 204 quantum computing security companies headquartered in the United States as of September 2026 and tracks 3,707 professional contacts across them, including 1,589 with verified work emails and 1,525 with mobile numbers. New York is the largest hub.

This list covers quantum computing security companies headquartered in the United States, matched on what each company actually does as described in its own words. Ranked by team size, largest first. Every row shows the company's own description, how directly it supports the match, and when it was last checked. Data refreshed September 5, 2026.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase SmartSearch, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.

How to read this list HQ checked on every row Match evidence on every row Refreshed Sep 5, 2026 86% judged on-target in blind review
204Companies
3,707Contacts tracked
1,589Verified emails
1,525Mobile numbers
Explore all 204 companies → Free signup · no credit card · 500 free credits

The 25 largest quantum computing security companies based in the United States

Ranked by team size
Top 25 of 204 quantum computing security companies based in the United States, ranked by team size, largest first. Data refreshed Sep 5, 2026. Evidence rates how directly each company's own description names quantum computing security companies: strong (names it), partial (names part of it), indirect (matched on its full profile rather than the summary shown). Click a count to unlock that company's people.
#CompanyHeadquartersEmployeesContacts
1
QuantinuumPartial evidence
Broomfield, CO, United StatesHQ checked Sep 5, 2026201-500598

“Science led and enterprise driven, Quantinuum unites Cambridge Quantum’s best-in-class software with Honeywell Quantum Solutions’ high-performing trapped-ion hardware.”

Source: company website · checked Sep 5, 2026
2
IONQStrong evidence
College Park, MD, United StatesHQ checked Sep 5, 20261,001-5,000574

“IonQ, Inc.[NYSE: IONQ] is the world’s leading quantum platform and foundry - delivering integrated quantum solutions across computing, networking, sensing, and security.”

Source: company website · checked Sep 5, 2026
3
InfleqtionStrong evidence
Louisville, CO, United StatesHQ checked Sep 5, 2026201-500211

“Infleqtion, Inc.(NYSE: INFQ) is a global leader in quantum technology, delivering neutral atom solutions for quantum computing, networking, sensing, and security.”

Source: company website · checked Sep 5, 2026
4
Rigetti ComputingStrong evidence
Berkeley, CA, United StatesHQ checked Sep 5, 202651-200171

“Rigetti is a pioneer in full-stack quantum computing.”

Source: company website · checked Sep 5, 2026
5
Quera Computing INCStrong evidence
Boston, MA, United StatesHQ checked Sep 5, 202651-200142

Quantum computing is moving from "one day" to "day one." QuEra Computing is leading that transition.”

Source: company website · checked Sep 5, 2026
6
Atom ComputingPartial evidence
Berkeley, CA, United StatesHQ checked Sep 5, 202651-20096

“We build scalable quantum computers with atomic arrays that empower our customers to achieve computational breakthroughs.”

Source: company website · checked Sep 5, 2026
7
NTT ResearchIndirect evidence
Sunnyvale, CA, United StatesHQ checked Sep 5, 2026201-50089

“Launched in 2019, NTT Research is a Silicon Valley-based startup dedicated to conducting fundamental research in the fields of physics, cryptography and medical informatics with a…”

Source: company website · checked Sep 5, 2026
8
Quantum Computing INCStrong evidence
Hoboken, NJ, United StatesHQ checked Sep 5, 2026201-50087

Quantum Computing Inc.(Nasdaq: QUBT) is a quantum optics and integrated photonics company focused on delivering accessible, scalable, and cost-effective quantum machines and…”

Source: company website · checked Sep 5, 2026
9
VIAIndirect evidence
Somerville, MA, United StatesHQ checked Sep 5, 202651-20086

“The U.S.”

Source: company website · checked Sep 5, 2026
10
Vector AtomicStrong evidence
Pleasanton, CA, United StatesHQ checked Sep 5, 202651-20059

“Vector Atomic is commercializing quantum technology for applications including GPS-free navigation, telecommunications, and computing.”

Source: company website · checked Sep 5, 2026
11
QusecureStrong evidence
San Mateo, CA, United StatesHQ checked Sep 5, 202651-20051

“For years, security leaders have been told that preparing for post-quantum cryptography (PQC) would take years, cost millions and require deep in-house expertise.”

Source: company website · checked Sep 5, 2026
12
QC Ware CorpStrong evidence
Palo Alto, CA, United StatesHQ checked Sep 5, 202611-5038

“QC Ware is a quantum computing software company building enterprise solutions.”

Source: company website · checked Sep 5, 2026
13
QRYPTIndirect evidence
New York, United StatesHQ checked Sep 5, 202611-5035

“Eternal Encryption.”

Source: company website · checked Sep 5, 2026
14
SEEQCStrong evidence
Elmsford, NY, United StatesHQ checked Sep 5, 202611-5034

“SEEQC is developing the first digital quantum computing platform for global businesses.”

Source: company website · checked Sep 5, 2026
15
StrangeworksPartial evidence
Austin, TX, United StatesHQ checked Sep 5, 202611-5031

“Strangeworks is an unconventional computing software company based in Austin, TX.”

Source: company website · checked Sep 5, 2026
16
EclypsesStrong evidence
Boston, MA, United StatesHQ checked Sep 5, 202611-5029

“Eclypses is redefining data security for the AI and quantum era.”

Source: company website · checked Sep 5, 2026
17
ALIROPartial evidence
Boston, MA, United StatesHQ checked Sep 5, 202611-5026

“Aliro, The Quantum Networking Company®, offers AliroNet® to run entanglement-based Quantum Networks for applications such as Quantum Secure Communications (QSC), secure access to…”

Source: company website · checked Sep 5, 2026
18
SafelogicIndirect evidence
Vienna, VA, United StatesHQ checked Sep 5, 202611-5022

“SafeLogic’s proven and validated cryptographic solutions enable enduring privacy and trust in the ever-changing digital world.”

Source: company website · checked Sep 5, 2026
19
HAIQUPartial evidence
Brooklyn, United StatesHQ checked Sep 5, 202611-5021

“Haiqu is a quantum software company developing a new application execution stack for all modalities of near-term quantum computers.”

Source: company website · checked Sep 5, 2026
20
Atlantic QuantumPartial evidence
Cambridge, MA, United StatesHQ checked Sep 5, 202611-5020

“Atlantic Quantum is now part of Google Quantum AI.”

Source: company website · checked Sep 5, 2026
21
ZksecurityPartial evidence
New York, United StatesHQ checked Sep 5, 202611-5017

Security audits, development, and research for ZKP, FHE, PQC, and MPC applications, and more generally advanced cryptography.”

Source: company website · checked Sep 5, 2026
22
Entrokey LabsStrong evidence
Mclean, VA, United StatesHQ checked Sep 5, 202611-5017

“Entrokey leverages generative AI to produce quantum-resistant random sequences, ensuring enhanced security against future quantum threats.”

Source: company website · checked Sep 5, 2026
23
Eeroq CorporationPartial evidence
Chicago, IL, United StatesHQ checked Sep 5, 202611-5016

“EeroQ is building a next-generation quantum computer using the technology of today.”

Source: company website · checked Sep 5, 2026
24
Quantum XchangeStrong evidence
Bethesda, MD, United StatesHQ checked Sep 5, 202611-5016

Quantum XChange protects the world’s data in motion from advances in computing and everyday cybersecurity risks.”

Source: company website · checked Sep 5, 2026
25
American BinaryStrong evidence
Kirkland, WA, United StatesHQ checked Sep 5, 202611-5016

“The only provably quantum-safe security for enterprise data in transit.”

Source: company website · checked Sep 5, 2026

Showing 25 of 204 quantum computing security companies based in the United States

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Quantum computing security companies based in the United States at a glance

As of Sep 5, 2026
11-50Median size (employees)
New YorkLargest hub · 12 HQs
1,525Contacts with mobile numbers
Sep 5, 2026Data refreshed

Companies by employee count

1-10
94
11-50
84
51-200
17
201-500
7
501-1,000
1
1,001-5,000
1

Verified emails by last verification

0–30
1,478
31–60
94
61–90
1
90–180
0
180+
16

How this list was built

Company categories are rarely black and white. RevenueBase reads each company's own description of its business to decide whether it belongs among quantum computing security companies, so some rows will be adjacent to the category rather than pure plays. The description and evidence rating on every row are there so you can check each match yourself.

Source
The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase SmartSearch, the natural-language company search available to every RevenueBase user.
What qualifies
Companies headquartered in the United States whose own description of what they do matches “quantum computing security companies”. Matching reads each company's description, not its industry code or its name.
What we exclude
Companies whose own description does not clearly place them among quantum computing security companies, and records with no verified work email. Companies headquartered outside United States are excluded even when they keep an office there.
Match quality
In blind human judging of this matching method, 86% of matched companies were on target. Expect roughly 1 in 7 rows to be adjacent to the category rather than a pure play. Every row shows the company's own description and an evidence rating so you can judge each match yourself. Read the full methodology: how the lists are built, how the judging worked, and what the figure means.
Ranking
Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
Verification
Every listed company carries at least one verified work email, 1,589 across the full list. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
Refresh
This page's figures were pulled from the company graph on September 5, 2026. Lists refresh periodically as the graph is re-checked.
Corrections
Wrong category, wrong headquarters, or a company that has closed? Use “Report an issue” on any row. Reports go to the RevenueBase Data Team and feed back into the company graph.

Frequently asked

How many quantum computing security companies are there based in the United States?

RevenueBase identified 204 quantum computing security companies headquartered in the United States as of September 2026, matched on each company's own description of what it does rather than its industry code.

What is the largest company on this list?

Quantinuum, headquartered in Broomfield, tops this list with the largest team on record.

Which city has the most quantum computing security companies?

New York leads with 12 headquartered companies, followed by Austin (8) and Chicago (7).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work the top results, verified emails and direct dials included. Upgrading unlocks all 1,589 verified decision-maker contacts tracked across these 204 companies.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on September 5, 2026.

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About this data

RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase SmartSearch, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.