When you are asked to log in with your CUHK account, you can have TWO things to check if it is “safe” to do: 

1. Is https://xxx.cuhk.edu.hk absent from the login website URL? 
   
   
2. For web applications verified by ITSC to provide login services, you can see either or all the following: 
   
   • You are directed to CUHK Login page (Single Sign-on Page) with the link and interface as below 
     
     
     
   • A CADS logo displayed at the login page with reference link to ITSC website e.g. 
     
     
     
   • The website is listed at CADS – Registered IT Systems.  

Certainly, you can always check with ITSC whether a website is legitimate in CUHK.  

A website owner in CUHK? 

If you have not yet joined our Central Authentication and Directory Service (CADS), please consider it. Your application can then enjoy a well-developed login service from us with regulatory security standards! You can also enable 2-factor authentication (2FA) through CADS to enhance login security. Check out the details at https://www.itsc.cuhk.edu.hk/all-it/information-security/centralized-authentication-and-directory-service/.