[Level 1] Password as plain text
[Level 2] Password encryption
[Level 3] Password hashing
[Level 4] Password hashing and salting
[Level 5] Cookies and sessions
[Level 6] OAuth 2.0 with Google
Login security test web
[Level 1] Password as plain text
[Level 2] Password encryption
[Level 3] Password hashing
[Level 4] Password hashing and salting
[Level 5] Cookies and sessions
[Level 6] OAuth 2.0 with Google