Is Security free to learn?

Yes. Every Security lesson on CodeMaster is completely free, with no ads. No login required to read the concept notes.

Can beginners follow Security?

Yes. Each lesson goes concept explanation → code example → interactive demo → quick quiz, so you can follow with no prior knowledge.

How long does Security take?

Each lesson is about 30–60 minutes. At 1–2 lessons a day you can finish the whole category in roughly 1–2 months.

Security - Security

🎯 After reading this lesson

After completing this lesson, you will be able to confidently do the following 3 things.

▸✅ Security patterns in "Security"
▸✅ OWASP (web security standards body) Top 10 mapping
▸✅ Real-world pitfalls (SQL Injection (DB tampering attack), XSS (script injection), CSRF (forged requests))

Keep the learning objectives as a checklist and close the lesson once you can answer all of them.

🔒 4 People Who Built Security — From Cryptography to Modern Web Security

01

Whitfield Diffie & Martin HellmanDiffie & Hellman

                      Pioneers of Public-Key CryptographyStanford University1944~ / 1945~
                    

The two who opened the door to public-key cryptography — the beginning of modern internet security

1976 Publication of 'New Directions in Cryptography' — first proposal of the public-key concept
1976 Publication of the Diffie-Hellman key exchange algorithm — the foundation of HTTPS, VPN, and SSH
1992 Joined Sun Microsystems — established security architecture (Diffie)
2015 Joint recipients of the Turing Award — contributions to public-key cryptography officially recognized

TLS, SSH, VPN — the mathematical foundation of all secure communications on the internetPUBLIC-KEY · Public Key Creator

02

Rivest · Shamir · AdlemanThe RSA Trio

                      Inventors of RSA AlgorithmMIT1947~ / 1952~ / 1945~
                    

RSA — the trio who turned Diffie-Hellman's concept into a practical algorithm

1977 Publication of the RSA public-key cryptographic algorithm at MIT — based on the hardness of integer factorization
1982 Founded RSA Security — pioneered the commercial encryption market
2000 RSA patent expired — ushering in an era of free worldwide use
2002 All three jointly received the Turing Award

RSA — the foundational cipher for TLS certificates, digital signatures, and e-commerceRSA · Algorithm Creator

03

Phil ZimmermannPhil Zimmermann

                      Creator of PGPPGP Inc. → Silent Circle1954~Present
                    

PGP — the father of email encryption that allowed individuals to resist government surveillance

1991 Released PGP (Pretty Good Privacy) 1.0 — popularized email encryption
1993 Investigation by the US government for violation of arms export control laws — case closed without charges in 1996
1997 Founded PGP Inc. and advanced the OpenPGP standardization effort
2012 Co-founded Silent Circle — end-to-end encrypted communications service

OpenPGP, GPG, end-to-end email encryption — a symbol of personal privacyPGP · Email Encryption

04

Bruce SchneierBruce Schneier

                      Cryptographer & Security AuthorCounterpane → IBM → Harvard1963~Present
                    

The conscience of modern security — an authority who designed algorithms and critiqued policy

1993 Designed the Blowfish symmetric-key cipher — free and unpatented
1996 Published 'Applied Cryptography' — established as the industry-standard textbook
1998 Presented Twofish — one of the five AES finalists
2016 Fellow at Harvard Kennedy School — recognized authority on security policy and privacy

Blowfish and Twofish designs + Schneier on Security — the standard for security thinkingMODERN SECURITY · Modern Security Authority

👥

In one line

Diffie & Hellman (public-key concept) → RSA Trio (practical algorithm) → Zimmermann (popularization) → Schneier (modern authority). These four teams built the skeleton of internet security.

Why You Need to Know Security

In one line: One vulnerability = company reputation damage, legal liability, and end of service. Security is not a last line of defense — it is fundamental design.

Tool Mapping

Area	Core Standard
Web vulnerabilities	OWASP Top 10 (list of the 10 most common web vulnerabilities)
Encryption	AES · RSA · ECDSA · TLS (data and communication encryption standards)
Authentication	bcrypt · argon2 (password hashing) · OAuth (delegated login via Google/Kakao) · JWT (signed authentication token)
Security headers	CSP (script allowlist policy) · HSTS (enforce HTTPS) · X-Frame-Options
Monitoring	Sentry · Datadog · WAF (web application firewall)
Secrets	HashiCorp Vault · AWS Secrets Manager (secure storage for secret keys)

5 Core Reasons

Reason	Meaning
XSS · CSRF (script injection · forged requests)	The most common web vulnerabilities. Missing one `escape` (neutralizing special characters) line → user account takeover
SQL Injection (DB tampering attack)	Not using parameterized queries → entire database exposed. `parameterized query` (value-separated query) is mandatory
HTTPS (encrypted HTTP)	Plaintext communication = packet interception. Free certificates make this a basic requirement
Hash algorithms (one-way password transformation)	MD5 and SHA1 are deprecated. Use only bcrypt · argon2 (modern standard)
OWASP Top 10 (list of top 10 vulnerabilities)	A staple in all backend interviews. Not knowing it means no job offer

Key point: Security is not a feature — it is a fundamental mindset. Once breached, recovery is impossible.

🤖 Try asking AI like this

Knowing the concepts from this lesson lets you give AI specific instructions. Not a vague "fix this" but a request with vocabulary — that is where token savings begin.

▸"Check this code for security vulnerabilities"
▸"Map the relevant OWASP Top 10 (top 10 web security vulnerabilities) items for this"
▸"Rewrite this password storage logic using bcrypt (modern password hashing standard)"

Why This Reduces Tokens

Without knowing the concepts, even after getting an AI response you have to ask "What is that?" again. That follow-up question is what eats tokens. Learn the concepts once and conversations end in one go.