The Forrester Wave™: Identity-As-A-Service, Q4 2017 Identity-as-a-service (IDaaS) solutions provide a simple way to control access and provide single sign-on (SSO) to software-as-a-service (SaaS) (and, to a lesser degree, on-premise) applications, and they require minimal initial implementation investment. To assess the state of the IDaaS market and see how the vendors stack up against each other, Forrester evaluated the strengths and weaknesses of top IDaaS vendors against 41 criteria. This analyst research report shows how each provider measures up and helps S&R professionals make the right choice.