No way to require passphrase on startup! - Google Pixel Questions & Answers

I just got my pixel, and found two very bitter disappointments. First, as expected, even an unrooted device will not pass safetynet (i.e., let you run android pay) if you've unlocked the bootloader.
Second, however, and a bit more of a shock, there appears to be no way to require a passphrase on bootup. The option on the nexus 5X and 6P that you get while selecting a PIN simply does not exist. So does this mean there is basically no way to secure my phone?
This is doubly infuriating. On one hand Google wants to prevent me from learning my own device encryption keys, supposedly in the name of security. But then on the other hand, they reserve the right to extract my keys themselves if they ever sign a backdoored bootloader (that can extract the now unencrypted keys from firmware).
For me the whole benefit of the fingerprint reader has been that it lets me select a very long boot passphrase, since I don't have to type it to unlock the phone. However, I'm now seriously considering removing the PIN from my lockscreen so I don't delude myself into storing anything of value on my phone.
Am I the only one super annoyed at these security developments?

Mine asks for my pin on first login.

Moogagot said:
Mine asks for my pin on first login.
Click to expand...
Click to collapse
Yes, but by the time it prompts for a PIN, it has clearly already decrypted the flash storage. So this means that if your bootloader is unlocked, someone could have messed with your system partition to bypass the lockscreen.

15xda said:
Yes, but by the time it prompts for a PIN, it has clearly already decrypted the flash storage. So this means that if your bootloader is unlocked, someone could have messed with your system partition to bypass the lockscreen.
Click to expand...
Click to collapse
That's not true. With device encrypted data and Direct Boot enabled, this restricted mode allows apps to perform limited actions and access non-personal data (i.e. specific system files), allowing it to boot up to the lock screen securely without any user interaction.
You have to enable it though, by going to developer options and selecting "covert to file encryption”. This WILL perform a factory reset though.

msaitta said:
That's not true. With device encrypted data and Direct Boot enabled, this restricted mode allows apps to perform limited actions and access non-personal data (i.e. specific system files), allowing it to boot up to the lock screen securely without any user interaction.
You have to enable it though, by going to developer options and selecting "covert to file encryption”. This WILL perform a factory reset though.
Click to expand...
Click to collapse
There is no "convert to file encryption" option in the developer options on the Pixel. Anyway, since the lock screen shows personal images and notifications and such, clearly a lot of data is available if someone decrypts the file system, even if there were an option to double-encrypt a few individual sensitive files. Anyway, what are the chances that every app developer encrypts every file I care about? This is why I want full device encryption, and I want full device encryption without storing my keys someplace where a backdoored bootloader can get at them.

15xda said:
Anyway, since the lock screen shows personal images and notifications and such, clearly a lot of data is available if someone decrypts the file system, even if there were an option to double-encrypt a few individual sensitive files.
Click to expand...
Click to collapse
Well, I stand partially corrected, actually. The device definitely seems to show some of my settings on reboot, like, for instance, volume. On the other hand, it can't receive VOIP calls (suggesting it doesn't have access to the SIP password I configured in the dialer), and incoming mobile calls don't show the contact name. So I guess it does offer some protection, but it's much harder to figure out what.

In case anyone lands on this thread, here is an explanation of what is happening on bootup:
https://developer.android.com/training/articles/direct-boot.html
The short answer is Pixel uses file-based-encryption now instead of disk-based encryption. I'm still not happy about this design because it somewhat reduces privacy and potentially complicates examining applications as root, but it's not as bad as I originally throught.

Related

[Q] Encryption

Hey there. Can't find any info about encryption and what it brings, so I'll just fire away a few questions about details for that matter. Not that I'm so obsessed with security, more like just curious about the possibility. And keeping things under protection is nice when dealing with business stuff.
What encryption brings? Only data in encrypted, or apps/system too?
Would someone be able to get something from TF by connecting it to a PC? Or he will fail even using ADB or nvflash?
How secure we're speaking about? Any info on encryption method and key length in bits.
If I forget my password, or any other weird thing happen, could I reset it with nvflash, loading new clean images? Maybe encrypted volumes are handled differently, and it's not so easy...
Clockwork Recovery. Would it work perfectly fine with encrypted tablet?
Custom ROMs (like Prime!). Any possible problems when messing with system files without total wipe?
Performance. How bad it could be affected? I'm not sure Tegra2 has RSA-optimized module built-in (or whatever method it's using).
Unlocking. Will I be prompted to enter password every time I see unlock screen, or only when I reboot?
Any known limitations, like password length (I like to set long passwords, it's more efficient and easier to remember).
Bump - heard that HC 3.2 enabled encryption at last. Anyone tried it and can answer any of my questions?
Never done it myself, but from information I read:
tixed said:
Hey there. Can't find any info about encryption and what it brings, so I'll just fire away a few questions about details for that matter. Not that I'm so obsessed with security, more like just curious about the possibility. And keeping things under protection is nice when dealing with business stuff.
What encryption brings? Only data in encrypted, or apps/system too?
Would someone be able to get something from TF by connecting it to a PC? Or he will fail even using ADB or nvflash?
How secure we're speaking about? Any info on encryption method and key length in bits.
If I forget my password, or any other weird thing happen, could I reset it with nvflash, loading new clean images? Maybe encrypted volumes are handled differently, and it's not so easy...
Clockwork Recovery. Would it work perfectly fine with encrypted tablet?
I guess this should be fine.
Custom ROMs (like Prime!). Any possible problems when messing with system files without total wipe?
Performance. How bad it could be affected? I'm not sure Tegra2 has RSA-optimized module built-in (or whatever method it's using).
I read that this would have lesser performance since it has to be decrypted on fly and also affects battery.
Unlocking. Will I be prompted to enter password every time I see unlock screen, or only when I reboot?
I guess every time when you unlock.
Any known limitations, like password length (I like to set long passwords, it's more efficient and easier to remember).
Click to expand...
Click to collapse
I found THIS little tid bit after a Google search.
I do know that it does NOT encrypt your removable MicroSD card or SD card. The encryption can take a considerable amount of time to encrypt all your data (1 to 3 hrs and has to be powered on and at 100%). It will require a PIN or Password prompt at power on and possibly for other data sensitive action. It will also allow for password mining which is the process by which you are required to reenter a new password after so long. Also once you encrypt the only way back is a factory reset. If you lose your PIN or Password your SOL about getting your sensitive data back.
You might be better off using an app that can encrypt individual files that you choose.
Cheers...
tixed said:
What encryption brings? Only data in encrypted, or apps/system too?
Would someone be able to get something from TF by connecting it to a PC? Or he will fail even using ADB or nvflash?
How secure we're speaking about? Any info on encryption method and key length in bits.
If I forget my password, or any other weird thing happen, could I reset it with nvflash, loading new clean images? Maybe encrypted volumes are handled differently, and it's not so easy...
Clockwork Recovery. Would it work perfectly fine with encrypted tablet?
Custom ROMs (like Prime!). Any possible problems when messing with system files without total wipe?
Performance. How bad it could be affected? I'm not sure Tegra2 has RSA-optimized module built-in (or whatever method it's using).
Unlocking. Will I be prompted to enter password every time I see unlock screen, or only when I reboot?
Any known limitations, like password length (I like to set long passwords, it's more efficient and easier to remember).
Click to expand...
Click to collapse
Had a brief experience with encryption before I wiped back to stock. I would strongly recommend against it unless you wish to stick to a stock system and very much need that type of security. From what I remember of my experience:
The data partition is encrypted (not sure what else, but not MicroSD). When your device boots, a prompt that somewhat resembles a lockscreen pops fairly early on when the OS attempts to mount those partition(s). Thereafter, everything is accessible as usual; you can grab things via ADB. You do not have to constantly enter the password (though you would probably want to lockscreen your device as general good practice). As to what nvflash would get you, I'm not sure, since that would be before the partition mount...probably nothing usable. The problem with having an encrypted partition is that CWM at moment can't really do anything useful to those partitions. You cannot flash, backup, or restore via CWM. This means your ability to work with custom ROMs is effectively crippled. In fact, to undo the encryption (or if you forget your password), I had to nvflash back to stock. Factory reset via CWM cannot be done since, again, the partitions are still encrypted.
If in the future, CWM is able to access the partitions like the stock recovery can, then you'd be fine. Performance was not noticeably slower in anyway.
Thanks for the replies. This feature seems pretty grim at the moment. Well, we can all hope that Google and ASUS will update it properly. At least, they did a lot of good updates recently.

Android Full Disk Encryption

I have thus far been unable to find the information I'm looking for in regards to full disk encryption for Android. When you encrypt the drive, Android uses the same password used for unlocking your phone. There are methods out there to defeat the lock screen. Does this bypass encryption as well?
I assume that if it's really encrypted then getting around the lock screen without the appropriate password/key combination would result in you being unable to access the data. If this is not the case then the question becomes whether or not the data can be considered encrypted while the hard drive remains on the phone.
Anyone have any practical knowledge of this, and of whether the key for turning the phone on is the same as for unlocking the phone? I would appreciate any input toward this discussion. Thank you!
-E
emccalment said:
I have thus far been unable to find the information I'm looking for in regards to full disk encryption for Android. When you encrypt the drive, Android uses the same password used for unlocking your phone. There are methods out there to defeat the lock screen. Does this bypass encryption as well?
I assume that if it's really encrypted then getting around the lock screen without the appropriate password/key combination would result in you being unable to access the data. If this is not the case then the question becomes whether or not the data can be considered encrypted while the hard drive remains on the phone.
Anyone have any practical knowledge of this, and of whether the key for turning the phone on is the same as for unlocking the phone? I would appreciate any input toward this discussion. Thank you!
-E
Click to expand...
Click to collapse
So, to be clear, any encryption can be bypassed. If the password is weak, then there is no issue and can be done in no time, if the password is strong (capital letters, numbers, symbols), then a brute-force attack can take years! Said that, you have to understand that Android devices has weaknesses, like every other device, and out there are also companies that guarantee they can decrypt any android device. Another way to decrypt an Android device is freezing the device at -10c (yes physically and no is not a joke). Researchers has demonstrated that if you freeze the device, and quickly disconnected and reconnected the battery will put the device in a vulnerable loophole. Even if encryption means data altering, and it requires a key to access/restore the data, this behavior probable occurs because the low temperatures causes data to fade from internal chips more slowly. That way is possible to obtain encryption keys and unscramble the phone's encrypted data. So, to reply to your question, yes, someone with enough knowledge can bypass your encryption.
Hey, thank you for your response! I read the article about bypassing encryption by slowing the rate of RAM fade and using FROST. I have a few minor follow on questions about that, however I'm not terribly concerned with tracking that down. I'm doing some research for a project, and I've just run out of time basically, so I can't try everything.
So, I know that it can be bypassed. I also know that you can run a kernel called Armored that supposedly keeps the keys for your encryption on the CPU instead of RAM, which supposedly shuts down cold boot attacks. I think that's a bit extreme for everyday situations, but it's there. I'm more curious about the authentication mechanism for the encryption I guess. It's ran through AES128, then salted with SHA, if I remember what I read. So without encryption, if you bypass the password, you're in. I'm curious, if you were to be able to bypass the encryption password (without actually getting it right). Would the system let you in, but leave everything encrypted and unreadable since you didn't provide the appropriate credentials?
-E
emccalment said:
Hey, thank you for your response! I read the article about bypassing encryption by slowing the rate of RAM fade and using FROST. I have a few minor follow on questions about that, however I'm not terribly concerned with tracking that down. I'm doing some research for a project, and I've just run out of time basically, so I can't try everything.
So, I know that it can be bypassed. I also know that you can run a kernel called Armored that supposedly keeps the keys for your encryption on the CPU instead of RAM, which supposedly shuts down cold boot attacks. I think that's a bit extreme for everyday situations, but it's there. I'm more curious about the authentication mechanism for the encryption I guess. It's ran through AES128, then salted with SHA, if I remember what I read. So without encryption, if you bypass the password, you're in. I'm curious, if you were to be able to bypass the encryption password (without actually getting it right). Would the system let you in, but leave everything encrypted and unreadable since you didn't provide the appropriate credentials?
-E
Click to expand...
Click to collapse
Encryption is carried out at boot time. After the device has booted, a lockscreen bypass will yield full access to the device's data. Encryption only protects your data when the phone isn't turned on, effectively. Or if you know the adversary won't be able to bypass the lockscreen, and would end up rebooting it without knowing it was encrypted.
pulser_g2 said:
Encryption is carried out at boot time. After the device has booted, a lockscreen bypass will yield full access to the device's data. Encryption only protects your data when the phone isn't turned on, effectively. Or if you know the adversary won't be able to bypass the lockscreen, and would end up rebooting it without knowing it was encrypted.
Click to expand...
Click to collapse
@pulser_g2 +++
Or if you have a tracking software that allows you to shut down your phone remotely... But in that case you may as well wipe your phone remotely.

Lollipop - Enabled encryption. Not sure if it worked

Hey guys
I flashed the factory images last night effectively wiping my Nexus 5 and starting from scratch. I did not restore apps and settings either. After I manually installed a bunch of my apps back and changed around a few settings, I decided to enable encryption. However, I don't think it enabled properly.
First, I had not set a PIN lock on my phone yet at the time.
When I decided to enable encryption and go through the process, it didn't ask me to enter a PIN.
It seemingly completed encrypting the phone. When I go back to the security menu, it says "Encrypted".
However, I am not prompted to enter a PIN upon booting the phone (not talking about the lock screen PIN).
So, it seems like it didn't work but I'm not sure. Has anyone else enabled encryption yet?
and yes, I saw the performance degradation that comes with enabling encryption but I'd rather have the security.
definitely sounds like there's an issue there. Do you have a custom recovery? If so, you could boot into that, pull some data and see if it opens. If it does, yeah its not encrypted.
Not worth mentioning degradation. All encryption always has and always will have performance degradation. It's par for the course
That sounds like a good idea. If it's not encrypted, then I guess the only method is to wipe and reinstall again.
mattkroeder said:
That sounds like a good idea. If it's not encrypted, then I guess the only method is to wipe and reinstall again.
Click to expand...
Click to collapse
I think so. You can't reverse the encryption flag without a wipe I dont think
mattkroeder said:
Hey guys
I flashed the factory images last night effectively wiping my Nexus 5 and starting from scratch. I did not restore apps and settings either. After I manually installed a bunch of my apps back and changed around a few settings, I decided to enable encryption. However, I don't think it enabled properly.
First, I had not set a PIN lock on my phone yet at the time.
When I decided to enable encryption and go through the process, it didn't ask me to enter a PIN.
It seemingly completed encrypting the phone. When I go back to the security menu, it says "Encrypted".
However, I am not prompted to enter a PIN upon booting the phone (not talking about the lock screen PIN).
So, it seems like it didn't work but I'm not sure. Has anyone else enabled encryption yet?
and yes, I saw the performance degradation that comes with enabling encryption but I'd rather have the security.
Click to expand...
Click to collapse
Not sure, but i think it's designed to works just like that, the encryption key is not the PIN anymore but something (random?) that is stored somewhere on the phone.
that would protect the data in case someone tries to read it directly from the phone's memory, but useless if you don;t have a PIN/PASSWORD.
I avoided encryption before for exactly that reason (requiring a password to boot). If I lose the phone I want the person that found/stole it to be able to at least boot it. if the person is not a thief there's a contact number so they can call me to give it back. if he/she's a thief well, as long as it's on I can call it, track it, wipe it. even brick it.
by not being able to boot it, the chances of getting it back are 0 if the battery dies or is dead!
http://readwrite.com/2014/10/28/google-android-lollipop-encryption-issues
there isn't much info out there about it.
kenshin33 said:
Not sure, but i think it's designed to works just like that, the encryption key is not the PIN anymore but something (random?) that is stored somewhere on the phone.
that would protect the data in case someone tries to read it directly from the phone's memory, but useless if you don;t have a PIN/PASSWORD.
I avoided encryption before for exactly that reason (requiring a password to boot). If I lose the phone I want the person that found/stole it to be able to at least boot it. if the person is not a thief there's a contact number so they can call me to give it back. if he/she's a thief well, as long as it's on I can call it, track it, wipe it. even brick it.
by not being able to boot it, the chances of getting it back are 0 if the battery dies or is dead!
http://readwrite.com/2014/10/28/google-android-lollipop-encryption-issues
there isn't much info out there about it.
Click to expand...
Click to collapse
I went ahead and wiped the phone again. I reinstalled lollipop and made sure to enable a lockscreen PIN before I enabled encryption. It seems to have encrypted properly. It prompts me for my PIN at boot up now.
You make a good point about encryption making it more difficult for someone to get a hold of me if I lose the phone though.
Same problem here, with Nexus 5 and Android v5
My work Exchange server enforces a security policy to the phone which forces you to enable encryption. So I went ahead and did that, and the email app is still saying that encryption needs to be enabled. When I reboot the phone I never get prompted for a PIN to decrypt the device, yet in the settings screen it says it is encrypted.
I'm going to have to re-flash. Is it possible the issue is caused by leaving the bootloader unlocked? or is this is a bug?
EDIT: Update. Reflashed, but first thing I did was relock the bootloader and enable a security screenlock PIN, *then* encrypted the phone. Now it's prompting me for a PIN on boot and looks like it's worked. Hope the Exchange email policy stays happy this time, as it worked before for about a day before it complained about the lack of encryption
this worked for me also
I did what was stated below and it worked....
1. reflashed,
2. locked bootloader
3. created lock pin
4. encrypted, THEN
5. added MDM control (MAAS360) and exchange email.
It seems to work OK now.
Thanks!
JoyrexJ9 said:
Same problem here, with Nexus 5 and Android v5
My work Exchange server enforces a security policy to the phone which forces you to enable encryption. So I went ahead and did that, and the email app is still saying that encryption needs to be enabled. When I reboot the phone I never get prompted for a PIN to decrypt the device, yet in the settings screen it says it is encrypted.
I'm going to have to re-flash. Is it possible the issue is caused by leaving the bootloader unlocked? or is this is a bug?
EDIT: Update. Reflashed, but first thing I did was relock the bootloader and enable a security screenlock PIN, *then* encrypted the phone. Now it's prompting me for a PIN on boot and looks like it's worked. Hope the Exchange email policy stays happy this time, as it worked before for about a day before it complained about the lack of encryption
Click to expand...
Click to collapse
mattkroeder said:
Hey guys
I flashed the factory images last night effectively wiping my Nexus 5 and starting from scratch. I did not restore apps and settings either. After I manually installed a bunch of my apps back and changed around a few settings, I decided to enable encryption. However, I don't think it enabled properly.
First, I had not set a PIN lock on my phone yet at the time.
When I decided to enable encryption and go through the process, it didn't ask me to enter a PIN.
It seemingly completed encrypting the phone. When I go back to the security menu, it says "Encrypted".
However, I am not prompted to enter a PIN upon booting the phone (not talking about the lock screen PIN).
So, it seems like it didn't work but I'm not sure. Has anyone else enabled encryption yet?
and yes, I saw the performance degradation that comes with enabling encryption but I'd rather have the security.
Click to expand...
Click to collapse
If you set up a screen lock pin the phone will ask you then if you would like the PIN to be enabled or not at boot.
kenshin33 said:
Not sure, but i think it's designed to works just like that, the encryption key is not the PIN anymore but something (random?) that is stored somewhere on the phone.
that would protect the data in case someone tries to read it directly from the phone's memory, but useless if you don;t have a PIN/PASSWORD.
I avoided encryption before for exactly that reason (requiring a password to boot). If I lose the phone I want the person that found/stole it to be able to at least boot it. if the person is not a thief there's a contact number so they can call me to give it back. if he/she's a thief well, as long as it's on I can call it, track it, wipe it. even brick it.
by not being able to boot it, the chances of getting it back are 0 if the battery dies or is dead!
http://readwrite.com/2014/10/28/google-android-lollipop-encryption-issues
there isn't much info out there about it.
Click to expand...
Click to collapse
Sorry for OT, but how can you remotely brick your phone? Just curious in case I ever need to. Don't live in the best of neighborhoods. I can remote wipe, track, take pics. The normal lost/stolen stuff, but I haven't heard of remotely bricking a phone ever.
Nexus 5 still looking to be encrypted
Only a temp fix---Both my Nexus 7, and Nexus 5 just started asked to be encrypted again....
This is still a problem with Lollipop
thegasmaster said:
I did what was stated below and it worked....
1. reflashed,
2. locked bootloader
3. created lock pin
4. encrypted, THEN
5. added MDM control (MAAS360) and exchange email.
It seems to work OK now.
Thanks!
Click to expand...
Click to collapse
wipe efs partition (I do have a backup on my computer) and the phone is no longer a phone.
Just to be clear, you can enable encryption on Android 5.0, and it will not force you to lock the phone. (Like the PIN screen and boot lock). When you buy a Nexus 6/9 the data partition is encrypted but there's no lock set. The following is from this article;
First, the encryption doesn't help much if you haven't set a passcode. Ludwig said studies have shown that roughly have of users don't set passcodes on their devices, largely because they find it inconvenient to keep entering them dozens of times a day. Lollipop will still encrypt your data, but it will also automatically decrypt it in normal use. So if you don't have a passcode, much of your information will be available to anyone who picks up your phone.
Click to expand...
Click to collapse
So if you've enabled encryption, and gone through the process, you're phone data partition is encrypted. It's just not locked down until you use some kind of phone lock too. BTW, the article goes on to describe the limited usefulness of having an encrypted data partition and no phone lock;
Lollipop's encryption still offers some limited protection even under those circumstances—for instance, by protecting stored data against anyone who tries to read it directly from the phone's memory. That could shield user passwords and other sensitive data from attackers.
Click to expand...
Click to collapse
As to why Exchange policies don't see the phone as encrypted is probably due to another issue.
Setting PIN to be required at startup after encryption possible fix
I now have my Nexus 5 & 7 working with exchange on Lollipop using this-
1. Reflashed Lollipop
2. Let phone reinstall all my apps
3. Locked bootloader.
4. Set a screen lock PIN
5. Encrypt phone
6. Set screen lock PIN to be required on start up (this was missing before!)
7. Installed MDM control via Mass360-all policies look to be met, including encryption
8. Installed my exchange account via Gmail
//code.google.com/p/android/issues/detail?id=79342
Updated thread with solution
---
* It used to be that when I did a reboot or shutdown and restart, I would have to enter a password before the system fully started.
* But now the phone boots into the phone without putting in my password. I can reboot the phone and it will boot all the way to the Lock screen, and I can unlock the lock screen with my fingerprint or my backup password.
* I am concerned that somehow my device is either no longer encrypted or that there is some setting which has stored the boot password.
--
Solution :
For those of you who find they have this problem and have not solved it, I found a solution that works, related to a bug (feature?) in Accessibility.
Apologies if this was suggested further in the thread, and that I'm replying to an old post. But I recently had this problem and figured out a solution.
- Accessibility was enabled and for some reason this cached the boot password. So- when I removed the app (rights) and turned off accessibility, and changed (reset/reentered) the password in security settings... On next boot the phone correctly asked me for password.
YMMV.
subs said:
I posted this elsewhere... But I'm having the same problem. Any thoughts? I can post more details, but don't want to repost this everywhere that I see people having the same unresolved problem.
---
* It used to be that when I did a reboot or shutdown and restart, I would have to enter a password before the system fully started.
* But now the phone boots into the phone without putting in my password. I can reboot the phone and it will boot all the way to the Lock screen, and I can unlock the lock screen with my fingerprint or my backup password.
* I am concerned that somehow my device is either no longer encrypted or that there is some setting which has stored the boot password.
Click to expand...
Click to collapse
Hi, please try not to bump threads almost a year old. I realise that it might have taken you a while to actually reach this thread, but hear me out.
Opening a new thread is always better, since software versions, features and devices are most likely different, along with different device usage habits/users.
You say you're having "the same problem"... as.. who exactly? There's a bunch of different specific "issues" that relate to encryption. Be specific.
For instance, you mentioning fingerprint sensor leads me to presume that you are not using a Nexus 5.
Sent from my Nexus 10 using Tapatalk

Making the S8+ completely theft proof

Hey!
It's my first post here so it this isn't the best place for such a question then by all means mods pls move the thread to where it should be
Basically, where I'm currently living (Brazil), things tend to get pretty violent and phone thefts are very common. Now the thing is, if it's an iPhone usually the thieves just throw it away, as once it's locked it becomes useless. When it comes to Android though, some of them will dig deep trying to access your info like pictures, passwords, bank information, among other things. They even manage to break IMEI locks and stuff. I got my S5 stolen recently and the information theft part put me through hell. Yet, I'd much rather have an S8+ then any other iPhone currently, so my question is how could I completely theft proof it?
I'm not really worried about them restoring the phone and reselling it, more about them accessing the data inside of it. I know the SD card can be protected through cryptography (although would accept "stronger" tips if there are any). When it comes to apps, aside from the basics of trusting what you install and stuff, are apps like Cerberus, Knox 2.0, or other Samsung features I'm not aware of, any good against someone who knows what they're doing? Is there a way to disable airplane mode or power offs? Also what is probably my strongest concern: is there a way to completely not allow system changes through a computer, like the one that removes the lock screen?
Being a programmer and computer science undergrad student (although not specializing in security nor mobile), I'd have no problem if the solutions would involve some coding or tweaking, just as long as they prove to be effective.
So, would you guys have any tips on how to completely secure the data given those concerns?
The sd card can be Encrypted and if you have a password lock (fingerprint irsi etc...) then it will ask for that before it will unlock the phone.
Also they have a remote wipe. You can log i to google and remote wipe your phone when you found out its been stolen.
You can set the phone to require a password to decrypt it when it's restarted. You can encrypt the SD card too. You can set it to lock instantly when the screen turns off. And you can use only a password to unlock it (no biometrics), which is the most secure option (if you use a suitable password). Finally, you can set the phone so that you can wipe it remotely, or to wipe itself after a number of consecutive incorrect password attempts. But even without the last two measures, your data will be unreadable without your password.
Unfortunately, though, if thieves are violent enough, they may be able to coerce you into divulging the password. If they succeed, they have full access to your phone.
Gary02468 said:
You can set the phone to require a password to decrypt it when it's restarted. You can encrypt the SD card too. You can set it to lock instantly when the screen turns off. And you can use only a password to unlock it (no biometrics), which is the most secure option (if you use a suitable password). Finally, you can set the phone so that you can wipe it remotely, or to wipe itself after a number of consecutive incorrect password attempts. But even without the last two measures, your data will be unreadable without your password.
Unfortunately, though, if thieves are violent enough, they may be able to coerce you into divulging the password. If they succeed, they have full access to your phone.
Click to expand...
Click to collapse
What about stuff like that Dr. Fone Toolkit that supposedly removes the lock screen? From the quick look I took it seems it somehow patches the Android on the phone to remove the lock screen. Is there some sort of system encryption/lock to avoid that kind of stuff when connected to a computer?
xile6 said:
The sd card can be Encrypted and if you have a password lock (fingerprint irsi etc...) then it will ask for that before it will unlock the phone.
Also they have a remote wipe. You can log i to google and remote wipe your phone when you found out its been stolen.
Click to expand...
Click to collapse
Usually they just put it on airplane mode though, so google remote wipe is useless... Which is why I was looking for more of an offline fix through cryptography and such
I use smart Lockscreen protector to prevent somebody putting my phone to airline mode or shutting it down ( It won't help phones with removable battery)
If you have the phone encrypted and have the require pin on boot set. And you have the Qualcomm version that is locked down you have nothing to worry about.
Even the iPhone 7 has been jail broken or rooted the S8 with the Qualcomm chip is one of only a few phones that have not been hacked. It's actually WAY more secure than an iPhone.
lvrma said:
What about stuff like that Dr. Fone Toolkit that supposedly removes the lock screen? From the quick look I took it seems it somehow patches the Android on the phone to remove the lock screen. Is there some sort of system encryption/lock to avoid that kind of stuff when connected to a computer?
Click to expand...
Click to collapse
The phone is completely encrypted, so if you set it to require a password to restart and to turn the screen back on, then its contents are unreadable without the password regardless of how you connect to it.
lvrma said:
...
Usually they just put it on airplane mode though, so google remote wipe is useless... Which is why I was looking for more of an offline fix through cryptography and such
Click to expand...
Click to collapse
If you have a lock screen set you can lock the status of your phone(wifi state, airplane mode, power settings). This way you have to unlock it to toggle these modes.
I just ran across this, some good advice.
http://thedroidguy.com/2017/04/setu...security-features-tutorials-1071462#Tutorial1
lvrma said:
What about stuff like that Dr. Fone Toolkit that supposedly removes the lock screen? From the quick look I took it seems it somehow patches the Android on the phone to remove the lock screen. Is there some sort of system encryption/lock to avoid that kind of stuff when connected to a computer?
Click to expand...
Click to collapse
Like you, I'm interested with this topic, but unlike you, I would like the theief to have a useless phone if they cant unlock it. So that they would think twice the next time they want to steal an android. Else they would just continue stealing since you just put the phone on download mode, connect to a computer and root it.
About your question. Isnt disabling usb debugging mode on developer option block that risk? Also in my note 4, enabling knox will prevent your device from being rooted, at least thats what i understand from the description. i wonder where it is in s8.
speaking of knox, s8 has "Secure folder". its like a secured environment within a phone. Everything you put in here will be protected by knox. Apps, accounts, files, etc. And it would ask for another security to access it(pattern/pin/password).
lvrma said:
Usually they just put it on airplane mode though, so google remote wipe is useless... Which is why I was looking for more of an offline fix through cryptography and such
Click to expand...
Click to collapse
you mentioned cerberus app, it has a function than can wipe device memory and wipe sd card via SMS command. so if you are fast enough, while the thief is running away and before he pulls out your sim card from the phone, you can send an sms command to wipe data.
Since you mentioned you are a programmer, this may be interesting to you, locking download mode and recovery mode on android to prevent thief from flashing hack to your phone. but this require a bit of patience if android isnt your forte.
https://ge0n0sis.github.io/posts/20...-mode-using-an-undocumented-feature-of-aboot/
BratPAQ said:
Like you, I'm interested with this topic, but unlike you, I would like the theief to have a useless phone if they cant unlock it. So that they would think twice the next time they want to steal an android. Else they would just continue stealing since you just put the phone on download mode, connect to a computer and root it.
About your question. Isnt disabling usb debugging mode on developer option block that risk? Also in my note 4, enabling knox will prevent your device from being rooted, at least thats what i understand from the description. i wonder where it is in s8.
speaking of knox, s8 has "Secure folder". its like a secured environment within a phone. Everything you put in here will be protected by knox. Apps, accounts, files, etc. And it would ask for another security to access it(pattern/pin/password).
you mentioned cerberus app, it has a function than can wipe device memory and wipe sd card via SMS command. so if you are fast enough, while the thief is running away and before he pulls out your sim card from the phone, you can send an sms command to wipe data.
Since you mentioned you are a programmer, this may be interesting to you, locking download mode and recovery mode on android to prevent thief from flashing hack to your phone. but this require a bit of patience if android isnt your forte.
https://ge0n0sis.github.io/posts/20...-mode-using-an-undocumented-feature-of-aboot/
Click to expand...
Click to collapse
Don't put your phone anywhere besides your pocket. Get a cover that makes it look like as different phone with a cracked screen.
the easiest way to encrypt sd and phone, enable adoptable storage.
cantenna said:
the easiest way to encrypt sd and phone, enable adoptable storage.
Click to expand...
Click to collapse
How is that easier than just selecting the Settings options to encrypt the SD card and to require a password to unlock upon restart?
---------- Post added at 06:08 AM ---------- Previous post was at 05:11 AM ----------
lvrma said:
Usually they just put it on airplane mode though, so google remote wipe is useless[.] Which is why I was looking for more of an offline fix through cryptography and such
Click to expand...
Click to collapse
Yes, and even without airplane mode, they can physically enclose the phone to block all electronic signals. Encrypting the phone (and SD card), using a secure password as the sole unlock method, affords the strongest protection against all attacks (except coercing the password from you).
Gary02468 said:
How is that easier than just selecting the Settings options to encrypt the SD card and to require a password to unlock upon restart?
---------- Post added at 06:08 AM ---------- Previous post was at 05:11 AM ----------
Yes, and even without airplane mode, they can physically enclose the phone to block all electronic signals. Encrypting the phone (and SD card), using a secure password as the sole unlock method, affords the strongest protection against all attacks (except coercing the password from you).
Click to expand...
Click to collapse
oh yea, may bad, i often assume everyone on xda is here because there interested in unlocked boot loaders, root and custom kernels. My recomindation applies only to people who have unlocked pandor's box only.
the method of encyption you suggested the isnt availble for users like me but we can enable adoptable storage which does encrypt the system by other means and it is compatible with root, etc
dynospectrum said:
Don't put your phone anywhere besides your pocket. Get a cover that makes it look like as different phone with a cracked screen.
Click to expand...
Click to collapse
Where can you get/ how can you make such a cover?
Also sometimes when I'm in bad Areas, I go to developer options and turn on some of the screen update stuff, so it flashes the screen purple a lot and make it look messed up.

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
Click to expand...
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.
Click to expand...
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.
Click to expand...
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.
Click to expand...
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
Click to expand...
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.
Click to expand...
Click to collapse
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.
Click to expand...
Click to collapse
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.
Click to expand...
Click to collapse
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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