# List of cybersecurity companies in Brittany

Tamtam tracks 37 cybersecurity companies headquartered in Brittany. This list ranks all of them by number of employees on LinkedIn, led by CS GROUP, SIB [numérique, santé et secteur public] and Hexatel. Their median headcount is 27. Half of them were founded in 2014 or later. The most common headquarters are Rennes (13), Cesson-Sévigné (6) and Brest (2).

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.

🇫🇷 Brittany · 37 companies · Updated Nov 11, 2026

| # | Company | Industry | Headquarters | Employees | Founded |
|---|---|---|---|---|---|
| 1 | [CS GROUP](https://www.tamtam.ai/c/cs-group) (cs-soprasteria.com)<br>Designs, builds, deploys, and maintains critical systems with innovative solutions and products, ensuring operational efficiency and security for client missions. | IT Services and IT Consulting | 🇫🇷 Le Plessis Robinson | 2,968 | 1968 |
| 2 | [SIB \[numérique, santé et secteur public\]](https://www.tamtam.ai/c/sib-numerique-sante-et-secteur-public) (sib.fr)<br>Innovative cooperative in digital health and public sector, serving 620+ institutions in modernizing their IT systems with a wide range of services and expertise | IT Services and IT Consulting | 🇫🇷 Rennes | 499 | 1993 |
| 3 | [Hexatel](https://www.tamtam.ai/c/hexatel) (hexatel.fr)<br>Support for businesses and communities in telecom, networks, and IT with personalized, high-quality, and carefully selected technology solutions. | Telecommunications | 🇫🇷 Noyal-sur-Vilaine | 257 | 1946 |
| 4 | [BLUE](https://www.tamtam.ai/c/blue) (bt-blue.com)<br>For over 15 years, this company specializes in providing high-speed network, data hosting, and unified communication solutions to professionals in a secure environment | IT System Data Services | 🇫🇷 Châteaubourg | 216 | 2005 |
| 5 | [Sekoia](https://www.tamtam.ai/c/sekoia) (sekoia.com)<br>Building a cyber operations platform for the AI era, unifying threat intelligence, detection, response, and exposure management, making advanced defense accessible. | Computer and Network Security | 🇫🇷 Rennes | 165 | 2022 |
| 6 | [Secure-IC](https://www.tamtam.ai/c/secure-ic) (secure-ic.com)<br>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 | Semiconductor Manufacturing | 🇫🇷 Cesson-Sévigné | 151 | 2010 |
| 7 | [Groupe Asten](https://www.tamtam.ai/c/groupe-asten) (groupe-asten.fr)<br>A company specializing in digital transformation, offering hosting, cybersecurity, custom software development, retail solutions, and consulting with a focus on Brittany's growth | IT Services and IT Consulting | 🇫🇷 Gouesnou | 150 | 1995 |
| 8 | [IDnow France](https://www.tamtam.ai/c/idnow-france) (idnow.io)<br>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 | IT Services and IT Consulting | 🇫🇷 Cesson-Sévigné | 119 | 2014 |
| 9 | [Eviden Identity & Access Management \| Home of Evidian](https://www.tamtam.ai/c/eviden-identity-and-access-management-home-of-evidian) (evidian.com)<br>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. | Software Development | 🇫🇷 Les Clayes sous Bois | 106 | 2000 |
| 10 | [Kereval](https://www.tamtam.ai/c/kereval) (kereval.com)<br>An independent testing engineering laboratory specializing in software quality, with 10 years of experience offering customized services to improve information systems and embedded systems | IT Services and IT Consulting | 🇫🇷 Thorigné Fouillard (Rennes) | 74 | 2002 |
| 11 | [GLIMPS](https://www.tamtam.ai/c/glimps) (glimps.re)<br>A French cybersecurity editor specializing in file analysis and malware detection using a unique technology called GLIMPS Deep Engine | Computer and Network Security | 🇫🇷 Cesson-Sévigné | 64 | 2019 |
| 12 | [Provectio](https://www.tamtam.ai/c/provectio) (provectio.fr)<br>IT services provider offering IT management, security, cloud computing, telecommunications, and network availability for businesses, providing support, strategy, and technical expertise | Telecommunications | 🇫🇷 Rennes | 48 | 2004 |
| 13 | [Groupe Pandora](https://www.tamtam.ai/c/groupe-pandora) (groupe-pandora.com)<br>Support for telecom and IT projects across northern France, offering technical expertise, personalized services, and strong team collaboration. | Telecommunications | 🇫🇷 Rennes | 42 | 2011 |
| 14 | [ORNISEC](https://www.tamtam.ai/c/ornisec) (ornisec.com)<br>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 | Computer and Network Security | 🇫🇷 Rennes | 35 | 2020 |
| 15 | [BLUECOM](https://www.tamtam.ai/c/bluecom) (bluecom.fr)<br>Bluecom specializes in managing organizations' information systems, providing network security, hosting, telephony, and IT solutions to enhance business performance | Computer and Network Security | 🇫🇷 Guipavas | 34 | 1996 |
| 16 | [ACCEIS](https://www.tamtam.ai/c/acceis) (acceis.fr)<br>ACCEIS is a cybersecurity expertise center providing tailored services including audit, consulting, training, and evaluation to secure clients' activities They prioritize excellence and client relationships | Business Consulting and Services | 🇫🇷 Rennes | 32 | 2015 |
| 17 | [DIATEAM](https://www.tamtam.ai/c/diateam) (diateam.net)<br>A European R&D company specializes in computer security, developing innovative cyber range platforms and industry-leading systems for cybersecurity training and testing labs | Computer and Network Security | 🇫🇷 Brest | 29 | 2002 |
| 18 | [EDSI](https://www.tamtam.ai/c/edsi-cesson-sevigne) (edsisecurity.com)<br>Specialized R&D company with 25 years of experience in Embedded Security, securing products and evaluating resistance to field attacks Subsidiary of Kudelski Group | Software Development | 🇫🇷 Cesson-Sévigné | 28 | 1990 |
| 19 | [RETIS Connected Solutions](https://www.tamtam.ai/c/retis-connected-solutions) (apixit.fr)<br>Specialized engineers design, deploy, and maintain network and security solutions with 24/7 hotline support for customer infrastructure supervision. | Computer Networking Products | 🇫🇷 Montauban-de-Bretagne | 27 | 1993 |
| 20 | [Ouest Consulting IP3G](https://www.tamtam.ai/c/ouest-consulting-ip3g) (ouest-consulting.net)<br>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 | IT Services and IT Consulting | 🇫🇷 Cesson-Sévigné | 26 |  |
| 21 | [Hogo](https://www.tamtam.ai/c/hogo) (hogo.eu)<br>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 | Computer and Network Security | 🇫🇷 Rennes | 26 | 2016 |
| 22 | [NOVASYS](https://www.tamtam.ai/c/novasys) (novasys.coop)<br>NOVASYS is a Cooperative and Participatory Limited Liability Company specializing in digital services for IT infrastructure deployment and management in Brittany | Computer Networking Products | 🇫🇷 Ploudaniel | 25 | 2012 |
| 23 | [BZHunt](https://www.tamtam.ai/c/bzhunt) (bzhunt.fr)<br>Helps anticipate cybersecurity risks for public and private sector players, using ethical hacking services. First French company in Bug Bounty competitions. | Computer and Network Security | 🇫🇷 Guipavas | 24 | 2020 |
| 24 | [IoT.bzh](https://www.tamtam.ai/c/iot-bzh) (iot.bzh)<br>Development and contribution to OpenSource embedded systems, focusing on automotive, telecom, TV, medical, military, and marine IoT sectors. | Software Development | 🇫🇷 Lorient | 22 |  |
| 25 | [Rubycat](https://www.tamtam.ai/c/rubycat) (rubycat.eu)<br>Publisher specializing in traceability and access control for sensitive information systems, reinforcing security policies for privileged users. Providing advanced audit tools. | Software Development | 🇫🇷 Cesson-Sévigné | 20 | 2014 |
| 26 | [Sensing Vision](https://www.tamtam.ai/c/sensing-vision) (sensingvision.com)<br>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 | IT Services and IT Consulting | 🇫🇷 Betton | 19 | 2017 |
| 27 | [A3BC GROUP](https://www.tamtam.ai/c/a3bc-group) (a3bc.io)<br>The company engineers biometric-based digital ID and strong authentication services to build trust in the physical, digital, and metaverse world | Computer and Network Security | 🇫🇷 Rennes | 16 | 2018 |
| 28 | [Cloud-IAM](https://www.tamtam.ai/c/cloud-iam) (cloud-iam.com)<br>Offers managed, secure identity and access management built on Keycloak, centralizing authentication, access rights, and user journeys for various users, ensuring compliance and support. | Computer and Network Security | 🇫🇷 Rennes | 16 | 2021 |
| 29 | [ETELCOM](https://www.tamtam.ai/c/etelcom) (etelcom.fr)<br>The company offers auditing, installation, maintenance, and security services along with selling related equipment for turnkey solutions with strong expertise in IT and networks | Computer and Network Security | 🇫🇷 Auray | 13 | 2019 |
| 30 | [Wallack](https://www.tamtam.ai/c/wallack) (wallack.fr)<br>Established in 2019 by 2 cybersecurity engineers, this company specializes in cybersecurity for SMEs and intermediate-sized businesses, offering services from strategy to implementation | Computer and Network Security | 🇫🇷 Le Rheu | 12 | 2019 |
| 31 | [Shadline](https://www.tamtam.ai/c/shadline) (shadline.fr)<br>An autonomous digital survival system providing collaborative tools and guaranteed data access to overcome cyber attacks and ensure business continuity | Computer and Network Security | 🇫🇷 Rennes | 9 | 2014 |
| 32 | [Sekost](https://www.tamtam.ai/c/sekost) (sekost.fr)<br>Specializing in cybersecurity diagnostics, our company helps organizations assess their security posture, identify issues, and facilitate rapid improvements in protection | Computer and Network Security | 🇫🇷 Rennes | 6 | 2021 |
| 33 | [Infrapro](https://www.tamtam.ai/c/infrapro) (infrapro.fr)<br>This company offers Digital remote services in various domains, specializing in Lean consulting, ERP integration, process optimization, website building, and software automation | IT Services and IT Consulting | 🇫🇷 Saint-Malo | 5 | 2024 |
| 34 | [CALIDRA](https://www.tamtam.ai/c/calidra) (calidra.io)<br>SaaS platform delivering personalized e-learning and phishing campaigns to enhance employee cybersecurity awareness and strengthen organizational defense. | Software Development | 🇫🇷 Rennes | 4 | 2023 |
| 35 | [FROGI SECURE](https://www.tamtam.ai/c/frogi-secure) (frogi-secure.com)<br>Development of a simple, customizable internet filtering device to control and restrict access to inappropriate or non-work-related websites in various environments. | Computer and Network Security | 🇫🇷 Brest | 4 | 2012 |
| 36 | [Malizen](https://www.tamtam.ai/c/malizen) (wallix.com)<br>The company provides data visualization and machine learning solutions to enhance cybersecurity team capabilities in a comprehensive visual environment | Computer and Network Security | 🇫🇷 Rennes | 4 | 2020 |
| 37 | [CYBEVAL](https://www.tamtam.ai/c/cybeval) (cybeval.fr)<br>Specializes in cyber security audits and verification, evaluating compliance with international, French, and European regulations, including mock audits and certifications like ISO27001 and HDS. | IT System Testing and Evaluation | 🇫🇷 | 1 | 2023 |

## How this list is built

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](https://www.tamtam.ai/l/largest-companies-brittany) (3,058)
- [Companies with in-house R&D in Brittany](https://www.tamtam.ai/l/r-and-d-companies-brittany) (366)
- [Retail chains in Brittany](https://www.tamtam.ai/l/retail-chains-brittany) (344)
- [Manufacturers in Brittany](https://www.tamtam.ai/l/manufacturers-brittany) (307)
- [Multinational companies in Brittany](https://www.tamtam.ai/l/multinational-companies-brittany) (264)
- [Family-owned companies in Brittany](https://www.tamtam.ai/l/family-owned-companies-brittany) (201)
- [Food and Beverage Manufacturing companies in Brittany](https://www.tamtam.ai/l/food-and-beverage-manufacturing-companies-brittany) (182)
- [Professional services firms in Brittany](https://www.tamtam.ai/l/professional-services-firms-brittany) (167)
- [Public sector organisations in Brittany](https://www.tamtam.ai/l/public-sector-organisations-brittany) (165)
- [Hardware manufacturers in Brittany](https://www.tamtam.ai/l/hardware-companies-brittany) (148)
- [Distributors and wholesalers in Brittany](https://www.tamtam.ai/l/distributors-and-wholesalers-brittany) (145)
- [Software Development companies in Brittany](https://www.tamtam.ai/l/software-development-companies-brittany) (132)
- [Food and beverage companies in Brittany](https://www.tamtam.ai/l/food-and-beverage-companies-brittany) (130)
- [SaaS companies in Brittany](https://www.tamtam.ai/l/saas-companies-brittany) (128)
- [Critical infrastructure operators in Brittany](https://www.tamtam.ai/l/critical-infrastructure-operators-brittany) (120)
- [Consumer goods companies in Brittany](https://www.tamtam.ai/l/consumer-goods-companies-brittany) (115)
- [IT services companies in Brittany](https://www.tamtam.ai/l/it-services-companies-brittany) (113)
- [Education providers in Brittany](https://www.tamtam.ai/l/education-companies-brittany) (112)
- [Agriculture companies in Brittany](https://www.tamtam.ai/l/agriculture-companies-brittany) (108)
- [Retail companies in Brittany](https://www.tamtam.ai/l/retail-companies-brittany) (107)
- [IT Services and IT Consulting companies in Brittany](https://www.tamtam.ai/l/it-services-and-it-consulting-companies-brittany) (101)
- [Consulting firms in Brittany](https://www.tamtam.ai/l/consulting-firms-brittany) (99)
- [Healthcare providers in Brittany](https://www.tamtam.ai/l/healthcare-providers-brittany) (97)
- [Contract manufacturers in Brittany](https://www.tamtam.ai/l/contract-manufacturers-brittany) (93)

## The same list elsewhere in France

- [Cybersecurity companies in France](https://www.tamtam.ai/l/cybersecurity-companies-france) (958)
- [Cybersecurity companies in Île-de-France](https://www.tamtam.ai/l/cybersecurity-companies-ile-de-france) (525)
- [Cybersecurity companies in the Hauts-de-Seine department](https://www.tamtam.ai/l/cybersecurity-companies-hauts-de-seine) (154)
- [Cybersecurity companies in Auvergne-Rhône-Alpes](https://www.tamtam.ai/l/cybersecurity-companies-auvergne-rhone-alpes) (91)
- [Cybersecurity companies in Occitanie](https://www.tamtam.ai/l/cybersecurity-companies-occitanie) (49)
- [Cybersecurity companies in Provence-Alpes-Côte d'Azur](https://www.tamtam.ai/l/cybersecurity-companies-provence-alpes-cote-dazur) (48)
- [Cybersecurity companies in the Rhône department](https://www.tamtam.ai/l/cybersecurity-companies-rhone) (48)
- [Cybersecurity companies in Hauts-de-France](https://www.tamtam.ai/l/cybersecurity-companies-hauts-de-france) (44)
- [Cybersecurity companies in Grand Est](https://www.tamtam.ai/l/cybersecurity-companies-grand-est) (40)
- [Cybersecurity companies in the Bouches-du-Rhône department](https://www.tamtam.ai/l/cybersecurity-companies-bouches-du-rhone) (36)
- [Cybersecurity companies in Nouvelle-Aquitaine](https://www.tamtam.ai/l/cybersecurity-companies-nouvelle-aquitaine) (35)
- [Cybersecurity companies in the Nord department](https://www.tamtam.ai/l/cybersecurity-companies-nord) (30)
- [Cybersecurity companies in Pays de la Loire](https://www.tamtam.ai/l/cybersecurity-companies-pays-de-la-loire) (28)
- [Cybersecurity companies in the Haute-Garonne department](https://www.tamtam.ai/l/cybersecurity-companies-haute-garonne) (27)
- [Cybersecurity companies in the Ille-et-Vilaine department](https://www.tamtam.ai/l/cybersecurity-companies-ille-et-vilaine) (25)
- [Cybersecurity companies in the Yvelines department](https://www.tamtam.ai/l/cybersecurity-companies-yvelines) (25)
- [Cybersecurity companies in Paris](https://www.tamtam.ai/l/cybersecurity-companies-paris) (290)

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Source: https://www.tamtam.ai/l/cybersecurity-companies-brittany