Details are scarce at the moment but this is what we are able to lay our hands on. Samsung Galaxy S9 may likely feature intelligent Scan.
Samsung might introduce a combo of face unlock and iris scanner in the Galaxy S9. Remnants of the feature were found in an APK teardown of an unreleased Oreo beta build. It repeatedly appeared in the code as “Intelligent Scan”.
Interestingly, the feature will employ both face unlock and iris scanners to achieve superior results than Face ID. The iris scanner has been in previous generation of Galaxy Note series phones but it remains fringe thing at readmore:

http://infocity.com.ng/2018/01/samsung-galaxy-s9-to-feature-face-unlock-iris-scan-dubbed-intelligent-scan.html