Digicert - Encryption & Authentication
hCaptcha - Do you use a captcha to keep out bots? hCaptcha is a drop-in replacement for reCAPTCHA that earns website owners money and helps companies get their data labeled.
Comodo - Comodo, the leading Internet Security Provider offers Free Antivirus, SSL Certificate and other Internet Security related products with complete protection
MTcaptcha - Enterprise Captcha solutions
GlobalSign - GlobalSign offers a range of SSL Certificates with the strongest 2048 bit encryption and value add features to ensure your website is protected.
GeeTest CAPTCHA - GeeTest protects your websites, mobile Apps and APIs from bot threats.