HTTPS works for me -- Although I don't think it always used to.
Congratulations with getting a man-in-the-middle in your browser. That is not the right certificate from the Cloudflare site. I have attached a screenshot below with yours (bogus) at the left and the proper one at the right. You can see it is the same cloudflare web site at the chain end but the upstream certificate chain is totally different. The proper certificate was issued by a public Certificate Authority "Comodo" which can be validated up the trust chain to another public CA "UserTrust". The bogus one was from a proprietary company "Kaspersky" and it was NOT issued to Cloudflare, it was issued to you, as the "Personal" keyword suggests. Yes I know who Kaspersky is but for now keep reading.
What appears to happen in your case is your local antivirus hijacked your certificate store and installed itself at the Root, decrypting and re-encrypting your https traffic, therefore acting effectively as a man-in-the-middle between secure web sites and your browser . You are now in full merci of Kaspersky firm to do with your traffic whatever they feel like today.
It was just recently that exact same type of thing caused big problems to computer manufacturer Lenovo who was installing adware on their computers. If you have not heard of it and/or want to understand how this sh!t works, google for "Lenovo superfish scandal" and read a few articles. While reading, replace "Superfish" to "Kaspersky" and you will get the picture of what's happening to you.
Yes, some people may say "Kaspersky is a well respected antivirus company so it is OK". Let me ask you though if you really feel comfortable knowing that all your online banking/shopping/passwords are now not point-to-point anymore and are being decrypted by some man-in-the-middle program on your computer and then re-encrypted before delivered to your browser.
if you dont, I'd say look in your antivirus program settings to disable scanning https traffic, if it is possible at all, then re-check https site certificates now point to a proper public CA and not some "personal" certificate.
As to the subject of this topic you can see with this and Lenovo case that https does not guarantee you confidentiality, it can be hijacked.