PKI & TLS Training: Learn It Properly
Practical TLS is taught by Ed Harmoush, founder of Practical Networking and a widely followed TLS and networking educator on YouTube.
Our free guides are built to fix a specific problem fast. But if you want to genuinely understand TLS and PKI end to end — why certificate chains validate, how the handshake actually works, what TLS 1.3 changed — the most complete structured course we've found is Practical TLS by Ed Harmoush, the engineer behind the Practical Networking YouTube channel.
Start with his free Module 1 and our own free guides, then step up to the full course when you want the deep, first-principles version. FixMyCert readers get 50% off with the code FixMyCert.
What Practical TLS covers
Eleven modules taking you from cryptographic basics all the way through advanced TLS topics:
- Cryptographic foundations: hashing, symmetric and asymmetric encryption, RSA, Diffie-Hellman
- X.509 certificates and keys
- Certificate validation and chains of trust
- Public Key Infrastructure (PKI)
- Cipher suites and key exchange
- The TLS/SSL handshake, step by step
- TLS 1.3 (three dedicated modules)
- TLS defenses: HSTS, CAA, and Certificate Transparency
- TLS attacks and known vulnerabilities
- HTTPS/TLS extensions: SNI, OCSP stapling, session resumption
- Decrypting TLS traffic in Wireshark
Who it's for — and who should skip it
It's for you if:
You work with certificates, PKI, or TLS troubleshooting and want durable, first-principles understanding rather than one-off fixes — certificate lifecycle management, Venafi or CA work, infrastructure and security engineering, or prepping for a security-focused role.
Skip it if:
You just need to fix one error right now. Our free guides cover the common ones — try the OpenSSL s_client guide or Certificate Transparency guide — and you don't need a course to unblock a broken certificate.
Start free first
Try before you buy. Ed offers the first module of Practical TLS free , and our own guides are free to read. If the free material clicks and you want the complete structured path, the full course is worth it.
Good starting points on FixMyCert: the ACME Protocol guide for certificate automation, Certificate Transparency for chain validation context, and the Compliance Hub for current CA/Browser Forum deadlines. Need a certificate right now? See our ZeroSSL guide.
Affiliate disclosure: FixMyCert is an affiliate of Practical Networking. If you enroll through our link we earn a 30% commission — and you pay 50% less than list price with our code FixMyCert. We recommend Practical TLS on its merits; both the discount and the commission come from our partnership with the instructor, at no extra cost to you (in fact, you pay less).