Author: qc_admin

What is public key cryptography? Learn how asymmetric key pairs enable encryption, digital signatures, TLS, and key exchange, plus practical pitfalls.

What is OAuth? Learn how OAuth 2.0 delegates authorization, why the authorization code flow with PKCE is preferred, tokens, scopes, and OpenID Connect.

What is a nonce? Learn how a number-used-once prevents replay attacks, powers Content Security Policy, secures OAuth and crypto, plus common pitfalls.

What is CORS? Learn how cross-origin resource sharing works, the preflight request, key response headers, and how to fix common CORS errors safely.

What is a CSRF token? Learn how anti-forgery tokens stop cross-site request forgery, where to place them, and common implementation mistakes to avoid.

What is a TLS handshake? The negotiation that authenticates a server and agrees on encryption keys before secure data flows. Learn TLS 1.2 vs 1.3 and pitfalls.

What is symmetric vs asymmetric encryption? One key versus a public/private key pair. Learn how each works, when to use them, and how they combine in TLS.

What is a rainbow table? A precomputed structure that reverses unsalted password hashes using a time-memory tradeoff. Learn how salts defeat it.

What is Argon2? The Password Hashing Competition winner, a memory-hard, salted algorithm. Learn its variants, parameters, and why Argon2id is recommended.

What is bcrypt? A slow, salted password hashing function with a tunable cost factor. Learn its hash format, the 72-byte limit, and how to use it safely.