The Certified OT Security Engineer (COSE) is an advanced, vendor-neutral certification for the engineers who secure industrial control systems without endangering the process they protect. It validates that you understand PLCs, SCADA, DCS and safety systems and the protocols that connect them, can assess risk by consequence and apply IEC 62443 zones, conduits and security levels, can design the industrial DMZ, segmentation, data diodes and brokered vendor access, can run OT asset, vulnerability and patch management around maintenance windows, can monitor passively, contain safely and recover from an incident, and can govern the program with operations and engineering at the table. The exam is computer adaptive and performance-based, and the credential is kept current through continuing education.
| Level | Advanced. An engineer-level credential: it assumes working experience in automation, networking or security and tests design and judgement, not definitions. |
|---|---|
| Delivery model | Computer adaptive, three stages. Your score on each stage selects the difficulty of the next, so no two candidates sit the same paper. |
| Format | 120 questions. A performance-based exam that includes performance-based questions and multiple-choice questions. No vendor product knowledge required. |
| Time | 180 minutes for the whole exam, timed. Autosaves every answer. |
| Scoring | You need a score of 700 out of 900 to pass. Results are reported on a scale of 100 to 900, and 700 corresponds to answering 72% of the exam correctly. Harder questions carry more weight, so a score means the same thing on any route. Multiple-response items and PBQs are all or nothing. |
| Retakes | No waiting period after a failed first attempt. Every attempt is paid for at the exam price. See the CertLabz Certification Retake Policy. |
| Voucher validity | 12 months from purchase, for one sitting. |
| Certification validity | 3 years. Renew with 75 CEUs per cycle and the $55 annual CE fee, or pass the current exam. Renewal details. |
| Language | English. |
| Credential | PDF certificate with QR code, public verification page, LinkedIn-ready credential ID. Issuer: CertLabz Certification Board. |
| Free resources | The exam objectives PDF and the ten sample questions PDF. |
| Workforce mapping | NICE Framework work roles: Operational Technology (OT) Cybersecurity Engineering (DD-WRL-009), Defensive Cybersecurity (PD-WRL-001). O*NET occupations: Information Security Engineers (15-1299.05). Self-declared by CertLabz, not reviewed by NIST or CISA. See the full mapping. |
A signed, verifiable:
The COSE is a performance-based exam: it includes performance-based questions alongside multiple-choice questions. Instead of only picking A, B, C or D, you place assets on the Purdue model, complete a conduit firewall policy, sequence the response to a rogue logic download, and choose the safe discovery method for fragile controllers. It is computer adaptive, is proctored and timed, needs no mandatory course, and tests securing real plants rather than reciting standards.
PLCs, RTUs, HMIs, SCADA, DCS and safety systems, the Purdue model, and why Modbus, DNP3 and OPC UA need different defences.
IEC 62443 zoning, default-deny conduits, protocol-aware firewalls, data diodes and brokered vendor access, designed for a real plant.
Passive discovery, ICS advisories, consequence-based prioritization, vendor-approved patching in windows and compensating controls.
Passive monitoring and baselining, safe containment with operations, verified logic recovery, Management of Change and safety-system isolation.
OT security is among the best-paid specialisms in the field because it needs engineers who understand both the plant and the adversary, and there are far fewer of them than open roles. Every route is shown here at once, so nothing is hidden behind a control you have to find.
United States pay reported by Glassdoor, checked September 2026. Pay varies by location, employer and experience. No certification guarantees a salary or a job.
| CertLabz COSE | GIAC GICSP | Limes/TÜV COSP | |
|---|---|---|---|
| What it is | Certification exam | Certification exam | Course with exam |
| Computer adaptive | Yes | No | No |
| Hands-on PBQs | Yes | No | No |
| Focus | OT security engineering | ICS security essentials | OT security foundations |
| Vendor neutral | Yes | Yes | Yes |
| Proctored | Yes | Yes | Yes |
| Questions | 120 | 82 | Not published |
| Time | 180 min | 180 min | Not published |
| Pass mark | 700 of 900 | 71% | Not published |
| Course required | No | No | Yes, 3 days |
| Exam voucher | $199 | $999 | €3,070 + VAT incl. course |
Compiled September 2026 from the GIAC pricing and GICSP pages and the Limes Security ICS.205 course page. Product names and trademarks belong to their owners; CertLabz is not affiliated with any of them. Confirm current details with each provider.
Six reasons this credential is worth your time, and worth an employer's attention.
One price for the exam, set by its level. Bundles add the study guide and hands-on practice at a saving.
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Every form is drawn from a bank of more than 130 items to these exact weights, whichever adaptive route you take. Filter by the area you want to study.
The exam runs in three stages. Your score on each stage selects the difficulty of the next, so a strong candidate is stretched and a struggling one is measured fairly rather than swamped. No two candidates sit the same paper. Harder questions carry more weight, so a scaled score means the same thing whichever route you took.
Each exam can have up to 5 to 12 performance-based questions, drawn fresh on every attempt, alongside the multiple-choice questions. A PBQ is a task rather than a list: you place assets in zones, complete a conduit policy, sequence an incident response, or match attacks to their lessons. They are scored all or nothing, so partial guesses do not pass.
Yes. Controllers, protocols, firewalls and monitoring tools are described generically using IEC 62443, NIST SP 800-82 and MITRE ATT&CK for ICS rather than one vendor's product. What you prove transfers across plants. Where a question involves a tool, it is described generically.
700 out of 900. Results are reported on a scale of 100 to 900, and 700 corresponds to answering 72% of the exam correctly.
There is no waiting period between a failed first attempt and a second attempt. Buy another voucher and sit the exam again when you are ready, and it will draw a fresh adaptive form from the bank. See the CertLabz Certification Retake Policy.
Yes, after three years. Keep it current by logging 75 CEUs during the cycle and paying the $55 annual CE fee before expiry, or by passing the current exam again.
The exam objectives PDF and the ten sample questions PDF. The COSE Official Study Guide is a $50 ebook, included in two of the bundles. Hands-on practice comes with the All Access plan, included in the Complete bundle.
A laptop or desktop with a webcam and microphone, Chrome, Edge or Firefox, a stable connection, and a quiet private room for three hours. Phones and tablets are not supported.
COSE is a continuing-education certification, like the CE credentials from CompTIA and ISC2. It is valid for three years from the day you pass. To keep it, log 75 continuing-education units during the cycle and pay the $55 annual CE fee before your expiry date. Or pass the current version of the exam again.
CEUs are logged from your CertLabz dashboard with supporting evidence. A certification that lapses can be reinstated only by passing the current exam.
Buy a voucher, study the objectives, sit the exam when you are ready. Your credential is issued the moment you pass.