IS UNLOCKED BOOTLOADER LESS SECURE/HOW TO MAKE SECURE? - Security Discussion

In what ways does having an unlocked bootloader make it easier for governments and (other) criminals to get into your device or data? Lots of people say "naaaaa it's not less secure, unlock your bootloader man... the data is ENCRYPTED" I know back in the day someone could just flash TWRP and delete the lockscreen! But now devices are encrypted and that can't be done anymore. I also experience that some security apps require root for their full features (Android Lost). But I'd think it'd be easier to inject some sort script or flash something to help them with trying to get into your device (like removing the unlock attempt limit like is done with iPhone). Luckily Oneplus can relock with custom ROM but most can't ) : .
If you wanna talk about specific devices, maybe talk about Xperia Z5 II and/or LG G8 Thinq. And whether it IS or ISN'T less secure, what can be done to BEST secure a device? Whether official or not.

A device with a locked bootloader will only boot the operating system currently on it. You can’t install a custom operating system – the bootloader will refuse to load it. If your Android phone has a standard locked bootloader when a thief gets his hands on it, he won’t be able to access the device’s data without knowing its PIN or password. (Of course, a very determined thief could crack open the phone and remove the storage to read it in another device.)
If you’re unlocking the bootloader of your device and want to protect against this, you could choose to enable Android’s encryption feature what dependes on Android version - either FBE ( default since Android 10 ) or FDE ( default since Android 6 ). This would ensure your data is stored in an encrypted form ( AES 256 ), so people wouldn’t be able to access your data without your encryption passphrase. However, even encryption can’t protect your data perfectly.
Conclusion:
Of course, you probably don’t need to worry about this too much. If you’re an Android geek installing custom ROMs and rooting your device for your own use, you probably aren’t going to be the target of a determined and skilled thief who wants to access the data on your device. If your device is stolen, it’s probably by someone who just wants to wipe the device and sell it. And this wiping can easily be done by connecting the Android phone via USB--cable with PC and from there launching a specific command.

Related

[Q] Broke the glass on my screen, now I have to give my phone to a technician...

Don't worry, it's a security question alright.
I live in Eastern Europe, which is on the far side of the Samsung support network and I have samsung galaxy s3 phone (GT-9300 i guess). My repair options look a little bit bleak. I must either ship it back to France, from where it is bought, or I must seek help of non-licensed technicians. Thank God, there are quite a lot around here and for problems like this they do wonders.
I am worried though that the technicians may try to meddle with the software of my phone and do something nasty with it while the phone is in their possession. I use the phone quite a lot to access various servers trough ssh and the servers contain semi-sensitive information about customers, phones, the equivalents of social security numbers in my country and etc. Of course I will delete my present information, but how about the future. If someone has hacked versions of the firmware, it will be a child game to get the passwords for my servers.
So I need to secure the software of my phone somehow and I'm not sure of my options, so I'm asking for advice which is better. I have experience with Linux, but about Android I'm a quite noob. I had my Amazon FireHD Tablet rooted and installed with CyanogenMOD, so I know a little bit about ROM images. The phone itself is unrooted with original software and is not locked to a carrier.
Should I:
1. Try to back up my entire ROM image?
There are various questions here. It looks that I cannot download standalone original ROM image directly from Samsung so I must back up mine. But in the bootloader (which opens with volume up/down + home + power) it seems that there are no options for backing up rom image, only for restoring trough ADB of SD card. Should I try to root, install alternative bootloader and then back up everything.
There is one very important sub-question here: Will the phone signal me somehow If someone replaces the original bootloader with say, non-signed one? What If someone changes the bootloader as well as the system image?
2. Should I try to ecrypt my phone.
I cannot get easily information about what exactly is encrypted. Pretty sure that the bootloader itself cannot be encrypted anyway. How about the system image. Is it encrypted ?
I'll be thanful for any help about these two ideas as well as any others?
If you are paying to have the repair done by an entity other than Samsung then you have a great option available. Just out of curiousity, what version of android are you running? If I were in your shoes, I would root the phone and install a custom recovery (either TWRP or Philz). This will allow you to take a complete nandroid backup of the phone to the external SD Card. Confirm the nandroid backup has been saved to the SD Card then remove the card from the phone and store it somewhere safe. Then perform a factory reset to completely wipe the phone and have your phone sent out to be fixed. When you get your phone back, insert the SD Card and restore from the backup. It will be just as you left it and the possibility that anyone has been able to access or tamper with your phone is almost nil... Apart from possibly large national security agencies whom are known for having catalogs of common electronic items that have been compromised in various ways.
I can't speak for your exact phone, but I am quite familiar with encryption as well as the US-model Galaxy S3's. Unfortunately Samsung is known for running their own encryption schemes with are different and most often weaker than the stock. Custom ROMs with generally have an implementation based on AOSP sources. A 4 digit PIN or common passphrase can be easily broken with either, but a sturdy encryption passphrase will almost certainly provide sufficient protection.
Without knowing the specifics of your phone and whatever TouchWiz it's running, I can say this much. If you enable encryption on your phone, it will encrypt /data (application data) at a very minimum. This will almost definitely not include /system. It will probably not include the external SD card or any of the actual applications (the .apk files). The encryption would keep your data secure at rest, but it wouldn't prevent a motivated attacker from installing a hidden malicious application in the system.
You are correct in that the bootloader cannot be encrypted.
84598432951
fadedout said:
If you are paying to have the repair done by an entity other than Samsung then you have a great option available. Just out of curiousity, what version of android are you running? If I were in your shoes, I would root the phone and install a custom recovery (either TWRP or Philz). This will allow you to take a complete nandroid backup of the phone to the external SD Card. Confirm the nandroid backup has been saved to the SD Card then remove the card from the phone and store it somewhere safe. Then perform a factory reset to completely wipe the phone and have your phone sent out to be fixed. When you get your phone back, insert the SD Card and restore from the backup. It will be just as you left it and the possibility that anyone has been able to access or tamper with your phone is almost nil... Apart from possibly large national security agencies whom are known for having catalogs of common electronic items that have been compromised in various ways.
I can't speak for your exact phone, but I am quite familiar with encryption as well as the US-model Galaxy S3's. Unfortunately Samsung is known for running their own encryption schemes with are different and most often weaker than the stock. Custom ROMs with generally have an implementation based on AOSP sources. A 4 digit PIN or common passphrase can be easily broken with either, but a sturdy encryption passphrase will almost certainly provide sufficient protection.
Without knowing the specifics of your phone and whatever TouchWiz it's running, I can say this much. If you enable encryption on your phone, it will encrypt /data (application data) at a very minimum. This will almost definitely not include /system. It will probably not include the external SD card or any of the actual applications (the .apk files). The encryption would keep your data secure at rest, but it wouldn't prevent a motivated attacker from installing a hidden malicious application in the system.
You are correct in that the bootloader cannot be encrypted.
Click to expand...
Click to collapse
Thank You for the informative answer!
I had to do this once and what I did was:
- Root phone (which I always wanted to do)
- Perform a full backup to SD card
- Remove SD card and perform a factory reset of the phone
Then off to repairs.
Once back, I did again a factory reset (just in case) and then restore the lot
Seems a lot to do, but I have some sensitive data on it and didn't want to risk it too much. Besides during the restore I took the opportunity to upgrade to 4.3 (at the time)
glass
why dnt you buy a chinese glass and change it yourself its so easy and cheap, around 10 euros or so? i did the same for my old phone

Some Security questions

Hello guys, i have a few question that i would like to ask.
My boss is considering S8 as his new phone and he need to know about device security.
1.If you encrypt device how tough it is for police to open it?
No criminal activity done but police is part of the fight between companies. And it is the cheapest fighting method.
2.Is it possible to wire the phone without hardware mod?
Like for example using some sort of wireless method or wireless activation of cam or microphone?
3.If i turn on wipe device after 10 bad password attempts is it wiped completely without any possible way of recovery?
There will be no SD card used. Only internal memory.
4.What is safer? S8 or iPhone 7 Plus
5.Can there be software sent and installed to phone without user interaction?
Thank you so much for your answers.
It's impossible to directly crack the phone's encryption if you use a secure password. The SD card can be securely encrypted as well. Biometric unlocking is less secure, if you set that up (though if you shut the phone down, only the password will unlock it). There is an option to have the phone wiped after multiple failed password entries, but that gives no extra protection from serious attackers who can copy the phone's storage and work from the copy rather than the original. So you need a secure, unguessable password.
Courts may be able to compel you to unlock your phone (or jail you until you comply). Different jurisdictions have different (and changing) rules on the matter.
All phones are designed with strong measures against installing malware. And the S8's Secure Folders feature adds another layer of safety. Nonetheless, vulnerabilities are discovered all the time. They're patched by monthly security updates, but new ones still pop up. So it's impossible to guarantee the absence of malware (including malware that uses the microphone). Empirically, however, it appears to be quite rare for a modern phone, with up-to-date patches and other best security practices, to be seriously compromised.
But of course your boss will need to do their own research and verify all these claims from reliable sources, not from unknown people on an internet forum.

[Q] [Nov 2017] Knox - Down sides of tripping it?

I have searched xda and stackexchange to get this answer but have not been able to get a comprehensive list of what all will go if I trip Knox. Some answers were very old so I wanna see what all will I lose now with the latest Knox in my S8+? Some of the things I already know but don't care about losing:
1. Samsung Warranty
2. Secure Folder
3. Samsung Pay
4. Banking Apps
My actual concern is about device security as a whole e.g. if my device gets stolen, then except the data in my Secure Folder being secure, is there any other advantage of Knox too? Like the thief wouldn't be able to boot up or use my phone or anything of the sorts? Or the internal storage would be encrypted and there'll be Secure Boot only with Knox? I plan to flash TWRP too so what all am I going to lose? It would be amazing if we get a complete list of Knox features.
If you disable FRP lock to use root stuff, any thief can simply install a new ROM to your device and get full access as an owner without any protection. If FRP lock is enabled (not rooted), the person who steals your phone has to know your Google account login to use the device, otherwise the phone will be a brick stuck in the setup process. When you get the phone back from the thief, you can login with your Google account and have access to the phone again.
If you want to root, go for it, but I don't really see the point right now. LineageOS is not a daily driver yet (amazing that it exists though!), Note 8 ROMs bring only a few new things like different Infinity wallpapers, and things that required root before (f.e ad blocking) can be now done without root.
My banking app works with root but the finger print option is not available because of root. only thing i do miss is secure folder as that does not work.

Regarding security & bootloader...

There are many sites selling Mix 3's some Chinese, some Global, some with locked bootloaders, and some with unlocked bootloaders, this thread is to help people "protect" the devices they have bought (or will buy).
It's through my understanding that the most "secure" way of protecting your phone & data from thief's is to have your bootloader locked, with no custom recovery, encryption on & usb debugging disabled right?
This is because with a unlocked bootloader, the thief has the ability to boot into TWRP (for example) & simply wipe your pin/password/lock off the phone completely, then just boot it up, factory reset it & sell it.
I know there is methods such as putting the phone in cold temperatures so you can retrieve the encryption keys from the RAM, but assuming the thief is just basic & what's to make some quick money off your phone...So...
What's the best way & most recommended thing to do with Xiaomi devices specifically, locked/unlocked, encrypted/not-encrypted, does it matter?, If not, why not?
Any help is appreciated! The more in-depth the better.
Even with a locked bootloader a thief can hold VolUp while booting, wipe phone and sell it. Wiping is possible in any case and thats not even the issue a stolen Phone is gone.
The issue are your data which can be stolen too when you have a unlocked bootloader. Simply boot to twrp connect usb and copy everything. But you can prevent that with encryption and enable "requires pattern to start". That way if your phone gets stolen the thief can still Install/use Twrp but he needs to enter a pattern to decrypt the storage. If he doesnt, twrp wont be able to read the partition and your data is safe. He can still wipe the Phone and sell it but you cant prevent that. I don't know if the pattern generates the encryption keys or retrieves them from somewhere but i'd assume it generates them, probably together with some device specific values, else that would be a flaw in my book. If someone could enlighten me here that'd be nice.
If your bootloader is locked he also can't access your data. Since stock recovers doesn't allow/support Usb-filetransfer. So a lockpattern is all you need there. Encryption shouldnt really matter against the normal thief.
I am going this way: Unlocked bootloader to get rid of Miui, Twrp to have a proper recovery menu, and encryption+pattern to save my data. Disable USB-Developer Options to prevent adb shenanigans.
But on the hand if you wan't to get really panariod a locked bootloader would be better since you still can read the system image from the phone from twrp, this means, and this is a easy way to do it, you could read it copy it to the pc and simply brutefroce the lockpattern. If you have the partitions you can simply try 3 patterns either it works or the phone locks itself up because you did 3 wrong. If it locks up you simply write the partitions back and try again. If you can do 3 in 30 seconds you are done in 45 days since there are only 390.000 different patterns on a 3x3 grid (which is what most people use since some Roms don't even allow for 4x4 or 5x5) but if you emulate it and can do 3 in 15 seconds you are down to 23 days. If you run it in 20 emulators you are done in 1 day. (That would be an awesome weekend project.) In emulation you could really optimize this since you can cut everything out what isn't needed for the attempt to encrypt the partition. you dont even need the screen to load, simply send the decryption module whatever the last module in the Numbers-from-touches-chain would have sent, everything that is loaded before the attempt to decrypt must be unencrypted therefore can be messed with, probably it's even universal across phones since that's a stock android thing. If it tries to write used attempts, save whatever what gets overwritten beforehand, let it write its thing, kill the process, revert changes and try again with the next set. Maybe you get it down to 3s or 4s for 3 attempts and boom you are at 6 hours to encrypt any android phone, no matter which version, with an unlocked bootloader which uses a 3x3 pattern. But your data would be really valueable to someone if they did this. You can't do that with a locked bootloader since you can't read the partitions or you could just use the 5x5 pattern, which you cant do on MIUI (i just tried and havent found where you could change it). But probably i have a giant oversight in there so this probably woudn't work
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On the other hand if you want to recover your phone you should make it as easy as possible to get the thief into your phone since you dont want them to run it off and wipe it. I DONT RECOMMEND THIS. But you could make a 2nd user who has no lock pattern on it. Concider your Data public at this point but while they are busy looking at your selfies you could use a app like prey to track the phone. But since Data are more important than a phone i'd never do or recommend that.
Or you could just buy a tin foil hat.
~phoeny~ said:
Even with a locked bootloader a thief can hold VolUp while booting, wipe phone and sell it. Wiping is possible in any case and thats not even the issue a stolen Phone is gone.
The issue are your data which can be stolen too when you have a unlocked bootloader. Simply boot to twrp connect usb and copy everything. But you can prevent that with encryption and enable "requires pattern to start". That way if your phone gets stolen the thief can still Install/use Twrp but he needs to enter a pattern to decrypt the storage. If he doesnt, twrp wont be able to read the partition and your data is safe. He can still wipe the Phone and sell it but you cant prevent that. I don't know if the pattern generates the encryption keys or retrieves them from somewhere but i'd assume it generates them, probably together with some device specific values, else that would be a flaw in my book. If someone could enlighten me here that'd be nice.
If your bootloader is locked he also can't access your data. Since stock recovers doesn't allow/support Usb-filetransfer. So a lockpattern is all you need there. Encryption shouldnt really matter against the normal thief.
I am going this way: Unlocked bootloader to get rid of Miui, Twrp to have a proper recovery menu, and encryption+pattern to save my data. Disable USB-Developer Options to prevent adb shenanigans.
But on the hand if you wan't to get really panariod a locked bootloader would be better since you still can read the system image from the phone from twrp, this means, and this is a easy way to do it, you could read it copy it to the pc and simply brutefroce the lockpattern. If you have the partitions you can simply try 3 patterns either it works or the phone locks itself up because you did 3 wrong. If it locks up you simply write the partitions back and try again. If you can do 3 in 30 seconds you are done in 45 days since there are only 390.000 different patterns on a 3x3 grid (which is what most people use since some Roms don't even allow for 4x4 or 5x5) but if you emulate it and can do 3 in 15 seconds you are down to 23 days. If you run it in 20 emulators you are done in 1 day. (That would be an awesome weekend project.) In emulation you could really optimize this since you can cut everything out what isn't needed for the attempt to encrypt the partition. you dont even need the screen to load, simply send the decryption module whatever the last module in the Numbers-from-touches-chain would have sent, everything that is loaded before the attempt to decrypt must be unencrypted therefore can be messed with, probably it's even universal across phones since that's a stock android thing. If it tries to write used attempts, save whatever what gets overwritten beforehand, let it write its thing, kill the process, revert changes and try again with the next set. Maybe you get it down to 3s or 4s for 3 attempts and boom you are at 6 hours to encrypt any android phone, no matter which version, with an unlocked bootloader which uses a 3x3 pattern. But your data would be really valueable to someone if they did this. You can't do that with a locked bootloader since you can't read the partitions or you could just use the 5x5 pattern, which you cant do on MIUI (i just tried and havent found where you could change it). But probably i have a giant oversight in there so this probably woudn't work
________________________________________________
On the other hand if you want to recover your phone you should make it as easy as possible to get the thief into your phone since you dont want them to run it off and wipe it. I DONT RECOMMEND THIS. But you could make a 2nd user who has no lock pattern on it. Concider your Data public at this point but while they are busy looking at your selfies you could use a app like prey to track the phone. But since Data are more important than a phone i'd never do or recommend that.
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Click to collapse
Really appreciate the time you took to type out this post, thankyou.

Question Security after rooting?

Hi!
I'm considering buying Pixel 6a for its worth at around 300USD worth but after using Android for several years, I'm concerned about security after rooting, like after theft etc.
Afaik, if bootloader is unlocked, the thief can just flash a new image and that's it!
It's different with iOS where icloud lock (even after jailbreak) can render the device practically unusable.
Can someone guide if some kind of google lock is a possibility nówadays with Android or newer versions of Android?
Are you looking at this from a data security standpoint? Or from "make sure its worthless to the thief".
Data security I believe is much more important than causing the phone to self destruct if stolen, and from a data security standpoint, you don't need to worry about root, because the data stored in the userdata partition is ENCRYPTED, and this encryption is tied to lockscreen security. In other words, they need to be able to legitimately get past the lockscreen in order to have unencumbered access to your data, regardless of what they change with respect to boot and system partitions.
If on the other hand, you're more worried about rendering the device worthless if stolen (i.e., thief can't actually use it), then you're actually talking about gooble's factory reset protection, which pretty much locks you to factory images, and locked bootloaders, and the "unlock bootloader" switch set to not-unlockable.
Factory reset protection works by forcing you to validate that you are the owner of the gooble account previously registered as owner of the device. It can be trivially bypassed as long as the "allow oem unlocking" flag is set to true, or the device has a 3rd party OS key installed, such as from grapheneos.
Also, having the device REPORTED as stolen if it is, will make it unable to connect to a cellular network, which pretty effectively makes it worthless.
Thanks for detailed answer. It answers my question.
While data is first priority, rendering device non-usable is also a deterrent.
Gotta find some ROMs which allow encryption tho. Thanks again
tarun0 said:
Thanks for detailed answer. It answers my question.
While data is first priority, rendering device non-usable is also a deterrent.
Gotta find some ROMs which allow encryption tho. Thanks again
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Click to collapse
It isn't a useful deterrent to theft, because they have to steal it first before they can find out if its been rendered useless or not. Its not like they'll return it if they find out that its useless.
tarun0 said:
Hi!
I'm considering buying Pixel 6a for its worth at around 300USD worth but after using Android for several years, I'm concerned about security after rooting, like after theft etc.
Afaik, if bootloader is unlocked, the thief can just flash a new image and that's it!
It's different with iOS where icloud lock (even after jailbreak) can render the device practically unusable.
Can someone guide if some kind of google lock is a possibility nówadays with Android or newer versions of Android?
Click to expand...
Click to collapse
You should be worried more about having unlocked bootloader as opposed to root.
Root can only be obtained via Magisk, which creates a layer making your System think that Magisk is a part of it. No root could be obtained other than through Magisk manager, and even then, you will get a prompt to allow root to an app or adb. You can provide time limited root or one time only for apps. In other words, root gives the user control. Your OS already has root regardless of Magisk. All Magisk does is give you the power to grant or deny root.
Locked vs unlocked bootloader: this is where you should be concerned. If your bootloader is unlocked, it might be possible to boot or flash a modified recovery or TWRP that will have full write access to your system partitions, which are not encrypted. Android, unlike Linux or Windows never encrypted anything but data partition, and a few years ago, Google dropped even that in favor of file encryption. So, your data partition is no longer encrypted, just the files. So, when TWRP has full access to your system, an adversary may succeed in removing your screen lock/password/pattern and force system to boot straight without any lock. Note, the attacker wouldn't have to deal with encryption at all, but rather use natural Android weakness, which is: the first boot after installing a brand new rom is always without password prompt. So, in this case, the attacker will have the full access to your data.
With locked bootloader, this is not possible, as all fastboot actions are disabled.
99.9% of custom roms require unlocked bootloader. Those few, which are available on locked bootloader, do not provide root. There are only 1 or 2 developments that can provide optional root + locked bootloader.
optimumpro said:
You should be worried more about having unlocked bootloader as opposed to root.
Root can only be obtained via Magisk, which creates a layer making your System think that Magisk is a part of it. No root could be obtained other than through Magisk manager, and even then, you will get a prompt to allow root to an app or adb. You can provide time limited root or one time only for apps. In other words, root gives the user control. Your OS already has root regardless of Magisk. All Magisk does is give you the power to grant or deny root.
Locked vs unlocked bootloader: this is where you should be concerned. If your bootloader is unlocked, it might be possible to boot or flash a modified recovery or TWRP that will have full write access to your system partitions, which are not encrypted. Android, unlike Linux or Windows never encrypted anything by data partition, and a few years ago, Google dropped even that in favor of file encryption. So, your data partition is no longer encrypted, just the files. So, when TWRP has full access to your system, an adversary may succeed in removing your screen lock/password/pattern and force system to boot straight without any lock. Note, the attacker wouldn't have to deal with encryption at all, but rather use natural Android weakness, which is: the first boot after installing a brand new rom is always without password prompt. So, in this case, the attacker will full access to your data.
With locked bootloader, this is not possible, as all fastboot actions are disabled.
99.9% of custom roms require unlocked bootloader. Those few, which are available on locked bootloader, do not provide root. There are only 1 or 2 developments that can provide optional root + locked bootloader.
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Click to collapse
Ahhh... So there are options albeit just 1 or 2 which can root with bootlocker locked!!
I thought it's just impossible to root without unlocking bootloader.
Thanks for the nice explanation
tarun0 said:
Ahhh... So there are options albeit just 1 or 2 which can root with bootlocker locked!!
I thought it's just impossible to root without unlocking bootloader.
Thanks for the nice explanation
Click to expand...
Click to collapse
Just my view: if I were you, I wouldn't buy any Pixels phone that has Titan chip in it. It is just one more reliance on such a 'bastion' of privacy as Google. Note Titan is closed source, and not only it deals with certificates, but it can also modify firmware. Here is Zdnet's description:
"The Titan chip manufacturing process generates unique keying material for each chip, and securely stores this material -- along with provenance information -- into a registry database. The contents of this database are cryptographically protected using keys maintained in an offline quorum-based Titan Certification Authority (CA).
"Individual Titan chips can generate Certificate Signing Requests (CSRs) directed at the Titan CA, which -- under the direction of a quorum of Titan identity administrators -- can verify the authenticity of the CSRs using the information in the registry database before issuing identity certificates."
So, each machine's individual key is stored with some 'magic' database maintained by Titan Certification Authority. In other words, an entity funded by three-letter agencies now has an additional database holding individual keys for each phone.
optimumpro said:
Just my view: if I were you, I wouldn't buy any Pixels phone that has Titan chip in it. It is just one more reliance on such a 'bastion' of privacy as Google. Note Titan is closed source, and not only it deals with certificates, but it can also modify firmware. Here is Zdnet's description:
"The Titan chip manufacturing process generates unique keying material for each chip, and securely stores this material -- along with provenance information -- into a registry database. The contents of this database are cryptographically protected using keys maintained in an offline quorum-based Titan Certification Authority (CA).
"Individual Titan chips can generate Certificate Signing Requests (CSRs) directed at the Titan CA, which -- under the direction of a quorum of Titan identity administrators -- can verify the authenticity of the CSRs using the information in the registry database before issuing identity certificates."
So, each machine's individual key is stored with some 'magic' database maintained by Titan Certification Authority. In other words, an entity funded by three-letter agencies now has an additional database holding individual keys for each phone.
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Click to collapse
Thanks for the opinion broski! But what brand are available there?
I don't like Samsung anymore because they destroy screen with update and don't help customers. Rest brand look more on papers but not in real.
tarun0 said:
Thanks for the opinion broski! But what brand are available there?
I don't like Samsung anymore because they destroy screen with update and don't help customers. Rest brand look more on papers but not in real.
Click to expand...
Click to collapse
Onepluses allow relocking bootloader on custom roms.
tarun0 said:
Thanks for the opinion broski! But what brand are available there?
I don't like Samsung anymore because they destroy screen with update and don't help customers. Rest brand look more on papers but not in real.
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Click to collapse
Don't be intimidated by the technical language - it's not as complicated as it seems. All hardware security modules come with a key that is installed at the factory and signed by the manufacturer. This initial key is only used to establish a basic level of trust, and the HSM will then generate a unique key for encrypting your data and performing attestation. This process is the same no matter what brand of device you use, whether it's an OnePlus, a pixel, or any other brand
Newer pixel models have a feature called ATTEST_KEY that allows each device to have its own unique keys. If one of these HSM keys were to be compromised, it wouldn't affect your security. However, rooting your phone can compromise your security and make verified boot ineffective, even if the bootloader is locked. If you value security, it's important not to root your phone
tarun0 said:
Ahhh... So there are options albeit just 1 or 2 which can root with bootlocker locked!!
I thought it's just impossible to root without unlocking bootloader.
Thanks for the nice explanation
Click to expand...
Click to collapse
This statement is incorrect. The Android user interface was not designed to handle permission prompts for root access. When you root your phone, you increase the potential for UI bugs that were previously not able to cause harm to become attack vectors that can be used to gain full access to your phone. Rooting also weakens the security of your phone by adding new permissive domains and making the *_app SELinux domains more permissive
It is heavily recommended to read this article https://madaidans-insecurities.github.io/android.html
tarun0 said:
Thanks for detailed answer. It answers my question.
While data is first priority, rendering device non-usable is also a deterrent.
Gotta find some ROMs which allow encryption tho. Thanks again
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Click to collapse
For the past five years, it has been required that all Android phones have encryption enabled by default. If you purchase a Pixel phone, it will come with encryption already enabled, but you can further enhance the security of the encryption by installing GrapheneOS as they increase the file name padding length to the maximum supported by the kernel make certain attacks harder.
Block-based encryption is generally considered to be less secure than file-based encryption because it uses a single key to encrypt all data, rather than multiple keys for individual files (which is what FBE does). Android 10 introduced metadata encryption, which encrypts the sector 0 on the data partition, making it inaccessible to attackers even when attempting to access the data through recovery mode. One of the main reasons file-based encryption is preferred over block-based encryption is that it is more difficult to verify the security of block-based encryption, and the algorithms used in block-based verification can be complex and challenging to implement correctly. Additionally, block-based encryption only encrypts data and does not provide any integrity checking, so if the data becomes corrupt, there is no way to detect it and the decryption process will continue. This can result in broken files at best and potentially allow attackers to tamper with or exploit the Linux kernel at worst, as noted by Linux kernel maintainers
optimumpro said:
So, when TWRP has full access to your system, an adversary may succeed in removing your screen lock/password/pattern and force system to boot straight without any lock. Note, the attacker wouldn't have to deal with encryption at all, but rather use natural Android weakness, which is: the first boot after installing a brand new rom is always without password prompt. So, in this case, the attacker will have the full access to your data.
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This quote is mostly (the bad part) FALSE. The decryption on the files cannot be performed until AFTER the device has been unlocked. If an attacker installs something that skips the lockscreen, the files will NOT be decrypted, since that lockscreen password/pin/pattern/etc. is needed to gain access to the key.
No matter what, whether the device bootloader is unlocked or not, or the device has root access or not... if the device is physically outside of the owner's control, it is necessary to assume that security on it has been compromised and should not be trusted. As the owner, you should assume that it has been backdoored, so wipe it fully and reinstall OS.
there is one exception, though. in AFU state, FBE is already decrypted (same as FDE)
https://bugs.xdavidhu.me/google/2022/11/10/accidental-70k-google-pixel-lock-screen-bypass
(does not concern powered off devices)
96carboard said:
Are you looking at this from a data security standpoint? Or from "make sure its worthless to the thief".
Data security I believe is much more important than causing the phone to self destruct if stolen, and from a data security standpoint, you don't need to worry about root, because the data stored in the userdata partition is ENCRYPTED, and this encryption is tied to lockscreen security. In other words, they need to be able to legitimately get past the lockscreen in order to have unencumbered access to your data, regardless of what they change with respect to boot and system partitions.
If on the other hand, you're more worried about rendering the device worthless if stolen (i.e., thief can't actually use it), then you're actually talking about gooble's factory reset protection, which pretty much locks you to factory images, and locked bootloaders, and the "unlock bootloader" switch set to not-unlockable.
Factory reset protection works by forcing you to validate that you are the owner of the gooble account previously registered as owner of the device. It can be trivially bypassed as long as the "allow oem unlocking" flag is set to true, or the device has a 3rd party OS key installed, such as from grapheneos.
Also, having the device REPORTED as stolen if it is, will make it unable to connect to a cellular network, which pretty effectively makes it worthless.
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Not all of this is really right on the head.
tarun0​
FRP is VERY easy to bypass. Takes me about 2 minutes on Android 13 Jan 2022 update on 7 Pro, 7, 6a, 6 pro, 6, 5a, 5, 4a 5g and the 4a. The data is wiped though, so it at least can't have data stolen, but the FRP is more like a fence with a gate that you can just reach the other side to unlock with a paper clip lol
As far as getting past lock screen, there's USB plug-in's that if a true back actor wanted to get into the phone, it bypasses usb debugging and can force test thousands of pins and patterns per minute without flagging the maximum attempt trigger. But again, what's the chance of a phone getting stolen by someone with that level of knowledge? 90% of phone thieves take it, run and sell it quick flip.
Also, with a custom Android recovery, adb commands are possible, so if the device is rooted with a custom recovery, there's ways to extract the lock screen file where its stored and use it. I don't think the recoveries based on LineageOS can do this, but TWRP definitely can as I've done it personally. So far there's no twrp for any android 13 device to my knowledge. Even the android 12 variants of twrp are shotty and barely function.
Dirty flashing a rom will also remove any passcode generally on a phone. and make data accessible.
Reporting it stolen only goes so far. You can spoof the IMEI if rooted or straight up change it if you have tools like MiracleBox
Long story short, an unlocked bootloader and a rooted android device make the device very insecure. The only roms out there that let you re-lock the bootloader after flashing the rom are Graphene and CalyxOS. And I really don't recommend calyx. Its a pile of ****. Don't root graphene either, as you'll have to leave the bootloader unlocked
TechX1991 said:
Dirty flashing a rom will also remove any passcode generally on a phone. and make data accessible.
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we are talking about FBE encryption, not old FDE encryption with default_password. do not claim what you haven't tested yourself. FBE is simply secure in BFU state. also against bruteforce as gatekeeper lives in TEE. after 140 attempts the timeout has increased to 1 day.
kindly read about how FBE works
https://android.stackexchange.com/a/241688

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