[Samsung Galaxy S10e Questions & Answers] dude777:
Hi Folks,

I hope you guys can shed some light into this, sorry if this is long and if this has been asked I'm sorry but I could not find the answers I was looking for, as some results they sound almost the same and some had not specified enough. So I hope the clever people here can explain a few things before I go ahead.

Background on my Phone (don't know if its relevant or not)

I own an Exynos SM-G970F, on One UI 3.1, June 2021 Update, this was purchased in Australia. Now that my phone is out of warranty I was thinking of installing a custom ROM. The main motivation was to reduce CPU usage and improve battery life.

I have installed a custom ROM and rooted my tablet for practice and it was easy to follow. I gotta say it was phenomenal how it brought back ancient hardware to buttery smooth performance of newer android versions. I wanted this same experience on my daily driver phone and there are some security based questions I would like to know.

Questions

1. First off unlocking the bootloader, I have read that it reduces your security of the phone as this allows hackers to gain access to your phone unlike a locked bootloader. As far as I understand the bootloader is to check if the system partition is a Samsung ROM. So in an unlocked state it will still load the kernel and run the system regardless if the ROM is Samsung or not, am I correct in this?

1a. If that's the case and if I installed the custom ROM and then locked the bootloader I would brick my phone right? as the bootloader is looking for a Samsung ROM but since it can't recognize the ROM it will boot loop.

1b. So in this case how would an unlocked bootloader make it vulnerable apart from accessing the OS? I'm thinking in a real word scenario if I were to lose my phone and someone found it, they could have means of access from an unlocked bootloader? but then again they could have access through custom recovery?

1c. Would it be necessary to lock a bootloader once you install a custom ROM? Do some custom ROM support signing bootloaders?

2. SafetyNet, as far as I understand this is a Google thing? like the app from Play store will check your system for any tampered software before functioning or at least warning the consequences of using the app in a custom ROM, is this right?

2a. So this could lead to some banking apps not working as it requires a SafetyNet pass on your device. But this only happens if you end up rooting your device? I understand Magisk is systemless root so the SafetyNet should pass in theory?

Primarily I'm concerned of the security and privacy of the phone but nothing is perfect, so there has to be some give and take with privacy and security? Though I will lose some privacy as I will install OpenGApps for some applications to work. So security would be the most important thing. What would be some best practices for a daily driver phone on custom ROM?

I imagine that hackers are not interested attacking an individual as this takes a lot of time and energy, unless they are bored or something like that.

Thanks for taking the time to read all this and if you can shed more information that would be great! I would like to learn more before giving the green light for custom ROM on my Samsung S10e.