Fig. 4
From: Multi-factor authentication for shibboleth identity providers
![Fig. 4](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Fs13174-020-00128-1/MediaObjects/13174_2020_128_Fig4_HTML.png)
Authentication process using Phone Prompt as the second factor
From: Multi-factor authentication for shibboleth identity providers
Authentication process using Phone Prompt as the second factor