PKI cybersecurity architect

Req ID:529386

At Alstom, we understand transport networks and what moves people. From high-speed trains, metros, monorails, and trams, to turnkey systems, services, infrastructure, signalling and digital mobility, we offer our diverse customers the broadest portfolio in the industry. Every day, more than 80 000 colleagues lead the way to greener and smarter mobility worldwide, connecting cities as we reduce carbon and replace cars.

OT PKI Architect

Role Summary

The OT PKI Architect is responsible for designing, implementing, and governing Public Key Infrastructure (PKI) solutions that secure Operational Technology (OT) environments. The role focuses on certificate lifecycle management, identity and trust services, device authentication, secure communications, and compliance across industrial control systems, manufacturing facilities, and critical infrastructure.

The architect works closely with OT engineers, cybersecurity teams, enterprise PKI teams, Project Cyber managers, bid manager and vendors to ensure secure and resilient certificate-based security solutions.

Key Responsibilities

PKI Architecture & Design

• Design and maintain enterprise and OT PKI architectures.
• Define certificate hierarchy, trust models, Certificate Authority (CA) structures, and security controls.
• Establish offline root CA and issuing CA strategies for OT environments.
• Develop certificate policies (CP) and certificate practice statements (CPS).
• Ensure high availability and disaster recovery for PKI services.

OT Security Integration

• Integrate PKI solutions with:
  • Signalling systems
  • Turnkey systems
  • Distributed Control Systems (DCS)
  • Industrial Control Systems (ICS)
• Secure machine-to-machine (M2M) communications.
• Implement mutual TLS (mTLS) authentication for industrial applications.
• Support Zero Trust initiatives within OT environments.

Certificate Lifecycle Management

• Design automated certificate enrolment and renewal processes.
• Implement certificate discovery and inventory management.
• Manage certificate issuance, renewal, revocation, and replacement.
• Reduce certificate-related outages through proactive monitoring.

Security Governance & Compliance

• Define PKI standards, policies, and operational procedures.
• Ensure compliance with:
  • IEC 62443
  • NIST Cybersecurity Framework
  • ISO 27001
  • Industry-specific regulations
• Conduct security risk assessments and architecture reviews.

Technical Leadership

• Lead PKI-related projects and transformation initiatives.
• Provide technical guidance to OT and cybersecurity teams.
• Evaluate PKI and certificate management technologies.
• Engage vendors and third-party partners on solution design.

Incident & Operational Support

• Support incident investigations involving certificates and cryptographic services.
• Troubleshoot PKI-related issues in OT environments.
• Support certificate recovery and business continuity plans.

Required Qualifications

Education

• Bachelor's degree in:
  • Computer Science engineering
  • Cybersecurity
  • Information Technology
  • Electronics Engineering

Experience

• 7+ years in Cybersecurity, PKI
• Experience designing enterprise-grade PKI solutions.
• Experience with critical infrastructure or industrial environment

Technical Skills

PKI & Cryptography

• Microsoft ADCS(Must have)
• EJBCA (Must have)
• DigiCert PKI Platform (Nice to have)
• Entrust PKI (nice to have)
• Keyfactor (nice to have)
• Venafi (nice to have)
• OpenSSL

Cryptographic Knowledge

• X.509 certificates
• TLS / SSL
• Mutual TLS (mTLS)
• RSA
• Hashing algorithms
• HSM technologies

OT Security Knowledge

• IEC 62443
• NIST SP 800-82
• Industrial networking protocols

Infrastructure

• Windows Server
• Linux
• Active Directory
• Azure PKI services
• Cloud security integrations

Preferred Certifications (nice to have)

• CISSP
• CCSP
• GIAC GICSP
• GIAC GRID
• Security+
• Microsoft Security Certifications
• ISA/IEC 62443 Cybersecurity Expert
• Global Industrial Cyber Security Professional (GICSP)

Key Competencies

• Enterprise Architecture
• Security Design
• Risk Assessment
• Stakeholder Management
• Problem Solving
• Technical Leadership
• Communication Skills
• Project Management

Works Closely With:

• PKI Service Managers
• OT Security Engineers
• SOC Teams
• BID Technical manager

You don't need to be a train enthusiast to thrive with us. We guarantee that when you step onto one of our trains with your friends or family, you'll be proud. If you're up for the challenge, we'd love to hear from you!

Additionally, in the face of environmental challenges, many employees are choosing to cycle for their commute. To support this approach, the Saint-Ouen site has suitable infrastructure (secure parking, maintenance and inflation stations, lockers, etc.).

Important to note

As a global business, we're an equal-opportunity employer that celebrates diversity across the 63 countries we operate in. We're committed to creating an inclusive workplace for everyone.