Software-as-a-service (SaaS) is gaining momentum for all business applications, including Unified Communications as a Service (UCaaS). In this context, user identity will play a key role in connecting the future fragmented communication suites in both corporations and cloud SaaS providers. However, SaaS solutions impose strong security challenges to the enterprise's Identity Management (IdM), since cloud services need to be provided with the employees’ identities. UCaaS solutions should therefore enforce security properties such as trust relationship, anonymity, or control on information disclosure. WebRTC is reinforcing the trend towards cloud-based UC by adding real-time voice and video capabilities into browsers. WebRTC does not tackle IdM, and hence it is not evident how WebRTC-based cloud services can meet the corporate requirements on IdM. In this paper, we discuss various IdM models for cloud-based corporate services, and we introduce the major requirements for managing user identities in UCaaS. We assess the impacts of these requirements on WebRTC-based UC services. We finally propose a slight modification of WebRTC to meet the corporate requirements on IdM. 
Unified communications as a service and WebRTC: An identity-centric perspective