NSS Labs report: Cloud Security Is an Enterprise Responsibility. Enterprise and cloud service providers have equally important roles to play in cloud security. When it comes to a breach, it’s the business and its IT and security departments that must shoulder the responsibility. The report concludes that it’s ultimately the responsibility of the enterprise to secure data. The most important part of cloud security is to get any agreement in writing in writing, the report says, to ensure that the roles and responsibilities of the cloud service provider and enterprise are clearly defined.”]