About DecipherU
A practice tool for certification exams, and a library of the things people look up while they study for one. I built it; I write it; it is free until September 2027.
The practice
The front page is a real exam question. You pick an answer, say how sure you are, and check. You get the right answer, the reason, and the document the question was written from: a NIST publication, an RFC, a vendor page. I write the questions from those documents, not from other people's question banks, because the exam is written from those documents too. There are 17 exams on the site; Security+, ISC2 CC and CySA+ have full banks, the rest are being written. Each exam has a timed mock where the vendor publishes a format, and a page that shows your readiness by domain, weighted the way the vendor weights the exam.
The library
Around the practice there is a library: 725 glossary terms, 28 certification guides, 71 role guides with salary data, 100 laws and regulations, 30 breach case studies traced to their primary sources, 100 short answers, interview questions by role, comparisons, career transitions, and a set of tools. Every page says where its facts came from and when I last checked them.
The data
Salary figures come from the Bureau of Labor Statistics and are labelled by year. Threat techniques cite MITRE ATT&CK by id. Vulnerabilities cite the NVD. Exam formats, fees and passing scores come from the certifying body's own page, and each guide shows the date it was verified. Where I give an opinion, it reads like one.
The sources · How the questions and readiness are built
What is kept
Your answers, the confidence you gave, and an exam date if you set one, under an anonymous id or your account. That is what the readiness readout is made from, and it is also the research: I want to know which kind of practice gets people through the exam. No ads, no selling data. The details are on what we keep.
Who writes it
I am Julian Calvo. I have a doctorate in learning sciences from the University of Miami and I have spent most of my career in B2B software sales and in teaching people how to get into technical work. DecipherU is operated by Bespoke Intermedia LLC. If something on the site is wrong, write to contact@decipheru.com and I will fix it and say so on the page.
More about me · Contribute a question · Teaching a class?
DecipherU is independent of CompTIA, ISC2 and every other certifying body named on the site; their certification names are their trademarks.