E-commerce is a booming part of the new-age business, enabling transactions to be carried out over the internet. E-commerce technology platforms are in high demand as the popularity of e-commerce grows, which is why it's crucial to have a reliable solution with stable security. In this chapter, the authors discuss several harnessing process and methodologies available over clod computing technologies for securing e-commerce in terms of security and secure payment processing. In terms of B2B business organization, addressing secure payment processing along with secure transactions places a major role in current research field. In this chapter, the authors provide a clear outline and ideas about the importance of cloud, several architecture and models availability, data encryption, threats and best practices along with the importance of choosing cloud technologies over e-commerce field.