Rebecca Shapiro has posted an article, “A History of Linux Kernel Module Signing“, introductory paragraph excerpted below:
This article was originally written back in 2014 to accompany the talk I gave at Shmoocon called “The History of Linux Kernel Module Signing”. It is a discussion of various Linux kernel module signing implementations while highlighting some of the motivating factors behind various design decisions. I decided it was about time to publish this write up, so here it is. I have not found kernel module signing implementations outside of those created by Red Hat and by the mainstream Linux developers so there may be other flavors of Linux module signing that I do not mention here. The information I present here is based on Linux developer mailing lists and source code I have found. I do not have an insider perspective of the implementation decisions. If you want the ground truth, you should go talk to those developers who are a part of the narrative I present here.
Full article:
http://www.cs.dartmouth.edu/~bx/blog/2015/10/02/a-history-of-linux-kernel-module-signing.html
Looking just at UEFI Secure Boot issues with Linux driver signing, Linux distros do vary in their strength, I wish someone would gather data about this behavior for the mainstream distros.
Firmware Security 