These are the largest cybersecurity companies in Brittany, primarily operating in IT services, telecommunications, and computer security. The list includes a mix of established firms and younger companies. CS GROUP, with nearly 3,000 employees, designs and maintains critical systems. Hexatel supports businesses in telecom and IT, while BLUE provides high-speed network and data hosting solutions. Sekoia builds cyber operations platforms, and GLIMPS specializes in file analysis and malware detection.
A notable pattern is the concentration of companies in and around Rennes, with SIB, Sekoia, IDnow France, Kereval, GLIMPS, Provectio, Groupe Pandora, and ORNISEC all headquartered there or in nearby Cesson-Sévigné or Thorigné Fouillard. Many of these companies, such as Sekoia (founded 2022) and ORNISEC (founded 2020), are relatively young, indicating recent growth in the region's cybersecurity sector.
| # | Company | Employees | |||
|---|---|---|---|---|---|
| 1 |
CS GROUPcs-soprasteria.com
Designs, builds, deploys, and maintains critical systems with innovative solutions and products, ensuring operational efficiency and security for client missions. |
2,968 | |||
| 2 |
SIB [numérique, santé et secteur public]sib.fr
Innovative cooperative in digital health and public sector, serving 620+ institutions in modernizing their IT systems with a wide range of services and expertise |
499 | |||
| 3 |
Hexatelhexatel.fr
Support for businesses and communities in telecom, networks, and IT with personalized, high-quality, and carefully selected technology solutions. |
257 | |||
| 4 |
BLUEbt-blue.com
For over 15 years, this company specializes in providing high-speed network, data hosting, and unified communication solutions to professionals in a secure environment |
216 | |||
| 5 |
Sekoiasekoia.com
Building a cyber operations platform for the AI era, unifying threat intelligence, detection, response, and exposure management, making advanced defense accessible. |
165 | |||
| 6 |
Secure-ICsecure-ic.com
Global provider of cybersecurity solutions for embedded systems & connected objects Offers end-to-end protection technologies, Secure Elements, & evaluation platforms Expanding worldwide with innovative approach |
151 | |||
| 7 |
Groupe Astengroupe-asten.fr
A company specializing in digital transformation, offering hosting, cybersecurity, custom software development, retail solutions, and consulting with a focus on Brittany's growth |
150 | |||
| 8 |
IDnow Franceidnow.io
The company is a leading European provider of identity verification solutions, aiming to make the digital world safer with a comprehensive range of secure verification methods |
119 | |||
| 9 |
Eviden Identity & Access Management | Home of Evidianevidian.com
This company offers identity and access management solutions. It protects digital identities and secures access to resources for businesses, public sector, defense organizations, and research institutions. |
106 | |||
| 10 |
Kerevalkereval.com
An independent testing engineering laboratory specializing in software quality, with 10 years of experience offering customized services to improve information systems and embedded systems |
74 | |||
| 11 | 64 | ||||
| 12 |
Provectioprovectio.fr
IT services provider offering IT management, security, cloud computing, telecommunications, and network availability for businesses, providing support, strategy, and technical expertise |
48 | |||
| 13 |
Groupe Pandoragroupe-pandora.com
Support for telecom and IT projects across northern France, offering technical expertise, personalized services, and strong team collaboration. |
42 | |||
| 14 |
ORNISECornisec.com
ORNISEC is a leading cybersecurity consultancy firm offering services such as advice, audits, training, compliance, crisis management, putting a focus on practical and hands-on approach |
35 | |||
| 15 |
BLUECOMbluecom.fr
Bluecom specializes in managing organizations' information systems, providing network security, hosting, telephony, and IT solutions to enhance business performance |
34 | |||
| 16 | 32 | ||||
| 17 |
DIATEAMdiateam.net
A European R&D company specializes in computer security, developing innovative cyber range platforms and industry-leading systems for cybersecurity training and testing labs |
29 | |||
| 18 |
EDSIedsisecurity.com
Specialized R&D company with 25 years of experience in Embedded Security, securing products and evaluating resistance to field attacks Subsidiary of Kudelski Group |
28 | |||
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| 19 |
RETIS Connected Solutionsapixit.fr
Specialized engineers design, deploy, and maintain network and security solutions with 24/7 hotline support for customer infrastructure supervision. |
27 | |||
| 20 |
Ouest Consulting IP3Gouest-consulting.net
OUEST CONSULTING IP3G specializes in infrastructure development and management, integrating cutting-edge IT, networking, and telecom technologies for businesses and local governments in Western France |
26 | |||
| 21 |
Hogohogo.eu
Specializing in cybersecurity, this company provides integrated solutions for securing data exchanges via removable devices and developing "White Stations" for French markets They offer decontamination and data transfer solutions, custom developments, and continuous innovation in cyber defense |
26 | |||
| 22 |
NOVASYSnovasys.coop
NOVASYS is a Cooperative and Participatory Limited Liability Company specializing in digital services for IT infrastructure deployment and management in Brittany |
25 | |||
| 23 | 24 | ||||
| 24 | 22 | ||||
| 25 |
Rubycatrubycat.eu
Publisher specializing in traceability and access control for sensitive information systems, reinforcing security policies for privileged users. Providing advanced audit tools. |
20 | |||
| 26 |
Sensing Visionsensingvision.com
Sensing Vision optimizes building operating costs through non-intrusive, cost-effective measurement solutions, personalized insights, data security, using IoT, AI, cloud, and open data technologies |
19 | |||
| 27 |
A3BC GROUPa3bc.io
The company engineers biometric-based digital ID and strong authentication services to build trust in the physical, digital, and metaverse world |
16 | |||
| 28 |
Cloud-IAMcloud-iam.com
Offers managed, secure identity and access management built on Keycloak, centralizing authentication, access rights, and user journeys for various users, ensuring compliance and support. |
16 | |||
| 29 |
ETELCOMetelcom.fr
The company offers auditing, installation, maintenance, and security services along with selling related equipment for turnkey solutions with strong expertise in IT and networks |
13 | |||
| 30 |
Wallackwallack.fr
Established in 2019 by 2 cybersecurity engineers, this company specializes in cybersecurity for SMEs and intermediate-sized businesses, offering services from strategy to implementation |
12 | |||
| 31 |
Shadlineshadline.fr
An autonomous digital survival system providing collaborative tools and guaranteed data access to overcome cyber attacks and ensure business continuity |
9 | |||
| 32 | 6 | ||||
| 33 |
Infraproinfrapro.fr
This company offers Digital remote services in various domains, specializing in Lean consulting, ERP integration, process optimization, website building, and software automation |
5 | |||
| 34 |
CALIDRAcalidra.io
SaaS platform delivering personalized e-learning and phishing campaigns to enhance employee cybersecurity awareness and strengthen organizational defense. |
4 | |||
| 35 |
FROGI SECUREfrogi-secure.com
Development of a simple, customizable internet filtering device to control and restrict access to inappropriate or non-work-related websites in various environments. |
4 | |||
| 36 |
Malizenwallix.com
The company provides data visualization and machine learning solutions to enhance cybersecurity team capabilities in a comprehensive visual environment |
4 | |||
| 37 |
CYBEVALcybeval.fr
Specializes in cyber security audits and verification, evaluating compliance with international, French, and European regulations, including mock audits and certifications like ISO27001 and HDS. |
1 | |||
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Every company on this list has a Tamtam company profile. The industry is the one the company gives on LinkedIn; categories such as SaaS or fintech are classified by Tamtam's AI from the company's website and LinkedIn page; and the headquarters city must match the company's own address. Companies are ranked by the number of employees on LinkedIn, and the list is refreshed every night. Classifications can be wrong, so treat the list as a starting point rather than an official ranking. Last updated Nov 11, 2026.
More company lists in Brittany
- The largest companies in Brittany 3,058
- Companies with in-house R&D in Brittany 366
- Retail chains in Brittany 344
- Manufacturers in Brittany 307
- Multinational companies in Brittany 264
- Family-owned companies in Brittany 201
- Food and Beverage Manufacturing companies in Brittany 182
- Professional services firms in Brittany 167
- Public sector organisations in Brittany 165
- Hardware manufacturers in Brittany 148
- Distributors and wholesalers in Brittany 145
- Software Development companies in Brittany 132
- Food and beverage companies in Brittany 130
- SaaS companies in Brittany 128
- Critical infrastructure operators in Brittany 120
- Consumer goods companies in Brittany 115
- IT services companies in Brittany 113
- Education providers in Brittany 112
- Agriculture companies in Brittany 108
- Retail companies in Brittany 107
- IT Services and IT Consulting companies in Brittany 101
- Consulting firms in Brittany 99
- Healthcare providers in Brittany 97
- Contract manufacturers in Brittany 93
The same list elsewhere in France
- Cybersecurity companies in France 958
- Cybersecurity companies in Île-de-France 525
- Cybersecurity companies in the Hauts-de-Seine department 154
- Cybersecurity companies in Auvergne-Rhône-Alpes 91
- Cybersecurity companies in Occitanie 49
- Cybersecurity companies in Provence-Alpes-Côte d'Azur 48
- Cybersecurity companies in the Rhône department 48
- Cybersecurity companies in Hauts-de-France 44
- Cybersecurity companies in Grand Est 40
- Cybersecurity companies in the Bouches-du-Rhône department 36
- Cybersecurity companies in Nouvelle-Aquitaine 35
- Cybersecurity companies in the Nord department 30
- Cybersecurity companies in Pays de la Loire 28
- Cybersecurity companies in the Haute-Garonne department 27
- Cybersecurity companies in the Ille-et-Vilaine department 25
- Cybersecurity companies in the Yvelines department 25
- Cybersecurity companies in Paris 290