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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).

🇫🇷 Brittany37 companiesUpdated Nov 11, 2026

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.

#CompanyIndustryHeadquarters EmployeesFounded
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.

IT Services and IT Consulting 🇫🇷 Le Plessis Robinson 2,968 1968
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

IT Services and IT Consulting 🇫🇷 Rennes 499 1993
3
Hexatelhexatel.fr

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
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

IT System Data Services 🇫🇷 Châteaubourg 216 2005
5
Sekoiasekoia.com

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-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

Semiconductor Manufacturing 🇫🇷 Cesson-Sévigné 151 2010
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

IT Services and IT Consulting 🇫🇷 Gouesnou 150 1995
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

IT Services and IT Consulting 🇫🇷 Cesson-Sévigné 119 2014
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.

Software Development 🇫🇷 Les Clayes sous Bois 106 2000
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

IT Services and IT Consulting 🇫🇷 Thorigné Fouillard (Rennes) 74 2002
11
GLIMPSglimps.re

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
Provectioprovectio.fr

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 Pandoragroupe-pandora.com

Support for telecom and IT projects across northern France, offering technical expertise, personalized services, and strong team collaboration.

Telecommunications 🇫🇷 Rennes 42 2011
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

Computer and Network Security 🇫🇷 Rennes 35 2020
15
BLUECOMbluecom.fr

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
ACCEISacceis.fr

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
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

Computer and Network Security 🇫🇷 Brest 29 2002
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

Software Development 🇫🇷 Cesson-Sévigné 28 1990

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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.

Computer Networking Products 🇫🇷 Montauban-de-Bretagne 27 1993
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

IT Services and IT Consulting 🇫🇷 Cesson-Sévigné 26 n/a
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

Computer and Network Security 🇫🇷 Rennes 26 2016
22
NOVASYSnovasys.coop

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
BZHuntbzhunt.fr

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.bzhiot.bzh

Development and contribution to OpenSource embedded systems, focusing on automotive, telecom, TV, medical, military, and marine IoT sectors.

Software Development 🇫🇷 Lorient 22 n/a
25
Rubycatrubycat.eu

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 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

IT Services and IT Consulting 🇫🇷 Betton 19 2017
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

Computer and Network Security 🇫🇷 Rennes 16 2018
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.

Computer and Network Security 🇫🇷 Rennes 16 2021
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

Computer and Network Security 🇫🇷 Auray 13 2019
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

Computer and Network Security 🇫🇷 Le Rheu 12 2019
31
Shadlineshadline.fr

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
Sekostsekost.fr

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
Infraproinfrapro.fr

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
CALIDRAcalidra.io

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 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.

Computer and Network Security 🇫🇷 Brest 4 2012
36
Malizenwallix.com

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
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.

IT System Testing and Evaluation 🇫🇷 1 2023

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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 same list elsewhere in France