The main reasons for this kind of message are...
1. Your System Time is not the real-time.
2. Google Chrome is not updated.
3. The sites SSL certificate has Expired.
4. The sites SSL certificate is not Installed properly.
5. The sites SSL certificate is not issued by a Trusted Certificate Authority (CA) or a self-signed certificate is used to secure a website.
6. The website is secured with an outdated 128-bit SSL.
7. The website is secured with an outdated SHA-1 Algorithm.
Most of these can't be addressed by you, as they involve the site you are trying to visit. The only ones that can be adjusted by you would be the first two. So you would need to make sure your computers time is set correctly and that you have the most recent update...