Accessing remote web sites using SSL connection https provides encryption over the web. Another important use is to prevent MITM man-in-the-middle attack, in which the attackers can easily fake the destination web sites from one of many different intercepting means. To most of web users, SSL https is the only available solution to protect themselves.
Secure way to access Self Signed or Untrusted web sites
It's often users would see similar warning from browsers.
There are many reasons why some legitimate sites are untrusted by browsers especially for those self signed sites. There's no excuse for anyone without manually checking the SSL certificate SHA1 fingerprint which may be obtained from sites supports through phone, post mail, other reliable channels, or from matching previous known SSL certificates SHA1 fingerprints.
Setting Up SSL Web Sites
Some CA certificate authorities do give away free SSL certificates.
Cheap 256-bit commercial SSL certificate can also remove the "Untrusted" warnings from properly installed web sites.
Free Self Sign Certificates
To create self signed sites, OpenSSL is available on Solaris, Linux, Mac OS X, BSD, OpenVMS, Microsoft Windows, and IBM OS/400 System i.
OpenSSL for Mac OS X instruction
OpenSSL for Windows OS can be download from