DecipherU is free practice for cybersecurity certification exams, with the source behind every answer, in English, Spanish and Portuguese.
Left of free access, which ends September 2027.
17 exams and 15 courses to practice, one free question, then a free account.
Courses
Fifteen courses written from primary sources, each with a checkpoint at the end. Free until September 2027.
Finish a course and get a certificate of completion from DecipherU verifying you completed it.
- SOC Analyst FundamentalsTriage an alert, write the analyst note, and explain the NIST 800-61 lifecycle in an interview.6 modules · 14 h
- Break In: Land Your First Cybersecurity JobPick a first role on purpose, build the portfolio that gets you screened in, and run the search week by week.10 modules · 18 h
- AI Security EngineeringDefend an LLM application and its agents: prompt injection, tool misuse, data leakage, and the tests that prove the fix.16 modules · 68 h
- Cloud Security FundamentalsRead an AWS, Azure or GCP account the way an auditor does: identity, network, logging, the shared responsibility line.6 modules · 16 h
- AI Governance and RiskWrite an AI policy a company can follow, mapped to the NIST AI RMF and the EU AI Act, with the risk register to match.12 modules · 49 h
- Cybersecurity Sales MasteryRun a discovery call with a CISO, price against the incumbent, and close without overselling what the product does.22 modules · 29 h
The library
What people look up while they study, with the number of entries in each collection today.
- Glossary725Terms defined in plain language, with the source.
- Acronyms146The abbreviations spelled out and explained.
- Certifications28What each exam covers, costs and is worth.
- Careers71Role guides: the work, the pay, the way in.
- Salaries71Pay by role and city, from federal data.
- Laws100Regulations you will be asked about, with the statute.
- Interview prep58Questions by role, and what a good answer contains.
- Comparisons72Role against role, cert against cert, city against city.
- Transitions40From one job into security, with a timeline.
- Companies350Who hires, what they build, where they are.
- Decipher Files30Breach case studies traced to their primary sources.
- Answers100Short answers to the questions people ask.
- Tools7Calculators and checkers you can use now.
- Assessments10Short readiness checks by specialty.
- Risk scoreHow exposed your current role is to automation.
How it works
- Answer. One question at a time, weakest domain first, and you say how sure you are.
- See the source. After you check you get the right answer and the reason, then the NIST publication, RFC or vendor page the question was written from.
- Watch the five domains fill. Your readiness is one number per exam domain, weighted the way the vendor weights the exam. A lucky guess counts less than a certain answer.
Try one question
A junior SOC analyst is documenting controls for the organization's authentication system. Multi-factor authentication is enforced for all administrative access; the help desk can override MFA on a documented exception basis with a 24-hour expiry. Which control category and type best describe the help-desk override capability under the SY0-701 control taxonomy?
One free Security+ question. Sign in for a free account to keep going.
Teaching a class? A class code groups your students' practice, in aggregate, at no cost.
Contribute a question. Write one with a primary source; the ones that hold up go into the free set.
Julian Calvo writes the questions. DecipherU is independent of CompTIA, ISC2 and every other certifying body named on the site; their certification names are their trademarks.