The OpenID Connect website says “OpenID Connect 1.0 is a simple identity layer on top of the OAuth 2.0 protocol.” and this gives an impression that OpenID Connect can be implemented easily and seamlessly on top of an existing OAuth 2.0 implementation. However, the truth is utterly different. IMHO, OpenID Connect is virtually OAuth 3.0.

Oh you know. Just some light reading on oauth and openId protocols. 🙃