Full Definition or Meme
When the exact nature of the user request is unknown, it is best to authentication in the least obtrusive manner, which is typically not at the highest level they might need later in the interchange.
Then general use case is where trust elevation must occur during the
An anti-use case was discovered when the NSA funded the Blacker
When mobile device became common it was early realized that the blacker solution was not feasible and progressive authentication was proposed for mobile devices and later specifically for Android devices.
- Tom Jones Trust Elevation Use Case https://wiki.idesg.org/wiki/index.php?title=Trust_Elevation_Use_Case
- Oriana Riva +3 Progressive authentication: deciding when to authenticate on mobile phones Published in: Proceedings Security'12 Proceedings of the 21st USENIX conference on Security symposium Pages 15-15 Bellevue, WA August 08 - 10, 2012, http://feihu.eng.ua.edu/NSF_CPS/year1/SP_paper1.pdf
- Jeffrey Warren, +3, Progressive Authentication on Android https://css.csail.mit.edu/6.858/2013/projects/jtwarren-vkgdaddy-vedha-vvelaga.pdf