Abstract: Method, system and infrastructures for managing certificates for platform providers are described. A platform provider provides a platform to host a plurality of virtual sites designated individually with custom specified hostnames. According to one aspect of the present invention, traffic originating from a web browser to a designated website with a hostname is directed to a server (herein “control server”) designed for serving a corresponding certificate to establish a secure session between the browser and the designated website being hosted on a server (herein “platform server”) operated by a platform provider. In operation, the corresponding certificate may be retrieved from a cache in or accessible by the control server, or the control server is caused to generate a certificate based on the access request from the browser after a verification process.