To cope with Policy to enforce Tier 0 and Tier 1 accounts to use Two Factor Authentication (2FA), a 2FA solution, DUO 2FA, is implemented for protecting our accounts.

After using DUO 2FA, an additional piece of information, i.e. a Duo Push Response / One-time Passcode, is needed during login, which can help protect your account from unauthorized access.

• IT Admin Staff: mandatory to use the 2FA according to the policy
• Other General Staff: recommend to use 2FA, opt-in is allowed

https://www.itsc.cuhk.edu.hk/en-gb/all-it/information-security/two-factor-authentication-2fa

ITSC Service Desk > Information Security > General Enquiry > 2FA
Or, check out FAQs