This article discusses how to generate an unencrypted private key and public certificate pair that is suitable for use with HTTPS, FTPS, and the administrative port for EFT Server. (To generate an encrypted key/certificate pair, refer to Generating an Encrypted Private Key and Self-Signed Public Certificate.) General Information. Jul 09, 2019 Public Key Infrastructure (PKI) security is about using two unique keys: the Public Key is encrypted within your SSL Certificate, while the Private Key is generated on your server and kept secret. All the information sent from a browser to a website server is encrypted with the Public Key, and gets decrypted on the server side with the Private Key. Reasons for importing keys include wanting to make a backup of a private key (generated keys are non-exportable, for security reasons), or if the private key is provided by an external source. This document will guide you through using the OpenSSL command line tool to generate a key pair which you can then import into a YubiKey.