For accessing Oracle Cloud Services securely and for authorized access, combination of Public and Private Keys are required. So before the process of creating a new Database Instance public and private keys should be generated. Below is the process for generating public/private key.
Tools Required: PuttyGen.
Download PuttyGen from: http://www.chiark.greenend.org.uk/~sgtatham/putty/download.html
Follow below steps to use PuttyGen to generate keys.
Open Putty Key Generator.
Accept the defaults with SSH-2 RSA and 2048. Click on Generate.