🔐 Every app has a login. But do you know what's happening under the hood? Here are the most common login mechanisms every developer (and tech enthusiast) should know: 𝗣𝗮𝘀𝘀𝘄𝗼𝗿𝗱-𝗕𝗮𝘀𝗲𝗱 𝗔𝘂𝘁𝗵𝗲𝗻𝘁𝗶𝗰𝗮𝘁𝗶𝗼𝗻 The most traditional method — user provides a username/email and a secret password. • Plain passwords (basic, least secure) • Hashed + salted passwords (bcrypt, Argon2, PBKDF2) • Password managers auto-fill strong, unique passwords 𝗠𝘂𝗹𝘁𝗶-𝗙𝗮𝗰𝘁𝗼𝗿 𝗔𝘂𝘁𝗵𝗲𝗻𝘁𝗶𝗰𝗮𝘁𝗶𝗼𝗻 (𝗠𝗙𝗔 / 𝟮𝗙𝗔) Combines two or more factors for stronger security: • Something you know — password, PIN • Something you have — OTP via SMS, authenticator app (TOTP/HOTP), hardware key • Something you are — biometrics 𝗢𝗧𝗣 (𝗢𝗻𝗲-𝗧𝗶𝗺𝗲 𝗣𝗮𝘀𝘀𝘄𝗼𝗿𝗱) A temporary, single-use code: • SMS OTP — code sent via text message • Email OTP — code sent to email • TOTP — Time-based (Google Authenticator, Authy) • HOTP — Counter-based OTPs 𝗣𝗮𝘀𝘀𝘄𝗼𝗿𝗱𝗹𝗲𝘀𝘀 𝗔𝘂𝘁𝗵𝗲𝗻𝘁𝗶𝗰𝗮𝘁𝗶𝗼𝗻 No password…