This document discusses protecting applications and data in public clouds using Imperva security solutions. It begins with an overview of cloud security challenges due to the shared responsibility model. It then describes Imperva's SecureSphere, Incapsula, and Skyfence solutions for securing applications in AWS and Azure. Reference architectures are provided for deploying the solutions on AWS and Azure. A case study describes how an online gaming company used Imperva SecureSphere WAF to protect their applications after moving them to AWS.