4 ms·

How do you know that the key for full disk encryption on Android is sent to Google?

by Flimm 11y ago

morganvachon 11y ago
The very fact that we have to ask is what bothers me. Microsoft plainly states that they store the key for full disk encryption, and offer the ability to generate a new key not stored by them (as covered in the article). They also offer BitLocker in their Pro and Enterprise OSes, for even finer grained, user controlled, offline encryption management. On the other hand, Google claims they don't store your Android disk encryption key, yet for all their other services, they do. (They also backtracked on encrypting MicroSD cards, leaving your actual valuable data exposed yet giving you a false sense of security, but that's a discussion for another day). Chrome syncing (and by extension Chrome OS), for example, is decrypted by your Google account login. You can set up a second, separate passphrase for those services, but again the key is definitely stored by them. Given that they have done some really shady stuff in the recent past (Chromium builds that download closed-source binaries after compiling from source and executing for the first time, etc.), I don't trust them as much as I trust Microsoft. And that's not a lot of trust in the first place.
rdudek 11y ago
How do we know they don't? But at least with Microsoft, there is a way to remove the encryption key from them. Few years ago, I helped a person unlock their quicken backup file with help of Intuit by calling their support number. User forgot the password he created for the backup and when he tried to restore, he was unable to do it. Intuit was able to unlock that file for him using a master password...
- schoen 11y ago
  > How do we know they don't? Maybe someone can resolve this question by asking Google, examining Android source code, finding relevant online documentation, or even monitoring what a new Android device does on the network when setting up FDE. I don't feel like this should be a big insoluble mystery for the ages; it's a basic security property of a largely open-source OS that's one of the most popular in the world. We could even ask Micah Lee to do a follow-up article directly addressing other operating systems' FDE key management behavior.
  - beeboop 11y ago
    You can't audit the firmware of the baseband processor, which is capable of sending the key to anyone, so there's not much point of auditing Android/asking Google. You cannot rely on any phone with a closed firmware baseband processor to be 100% secure. It might also come as a surprise to many than most every post-2008 Intel processor is similarly insecure: http://libreboot.org/faq/#intel http://libreboot.org/faq/#intel
    - simoncion 11y ago
      > You cannot rely on any phone with a closed firmware baseband processor to be 100% secure. That's not the question being asked. The question being asked is: "How do you know that the key for full disk encryption on Android is sent to Google?" Every technical person understands that any part of a system that has unrestricted read access to RAM can be used to thwart any FDE scheme. For the purposes of this conversation, it's not useful to talk about this. Doing so is like saying "One can be instantly vaporized by a nuclear bomb, therefore the question is irrelevant." in a conversation about whether aspirin or ibuprofen is safer for occasional relief of minor pain.
      - beeboop 11y ago
        My post does not answer that question and it wasn't trying to. The answer to that question is "We don't know". But suggesting that we do an audit of the code to find out doesn't seem productive, which is what I was responding to. That's a terrible analogy. It would be more accurate to compare this to aspirin and ibuprofen both sharing an unknown compound known to be capable of easily killing someone when the manufacturer wants it to, then suggesting we audit both aspirin and ibuprofen of their known compounds to make sure they don't have anything capable of killing someone. It doesn't really matter if it does, because you don't want to use aspirin or ibuprofen if you want to guarantee you won't die through someone's arbitrary decision, in the same way you wouldn't use Android on a phone if you want to guarantee security of your data.
        schoen 11y ago

How do you know that the key for full disk encryption on Android is sent to Google?

by Flimm 11y ago

How do you know that the key for full disk encryption on Android is sent to Google?

The very fact that we have to ask is what bothers me. Microsoft plainly states that they store the key for full disk encryption, and offer the ability to generate a new key not stored by them (as covered in the article). They also offer BitLocker in their Pro and Enterprise OSes, for even finer grained, user controlled, offline encryption management. On the other hand, Google claims they don't store your Android disk encryption key, yet for all their other services, they do. (They also backtracked on encrypting MicroSD cards, leaving your actual valuable data exposed yet giving you a false sense of security, but that's a discussion for another day). Chrome syncing (and by extension Chrome OS), for example, is decrypted by your Google account login. You can set up a second, separate passphrase for those services, but again the key is definitely stored by them. Given that they have done some really shady stuff in the recent past (Chromium builds that download closed-source binaries after compiling from source and executing for the first time, etc.), I don't trust them as much as I trust Microsoft. And that's not a lot of trust in the first place.

rdudek 11y ago

How do we know they don't? But at least with Microsoft, there is a way to remove the encryption key from them. Few years ago, I helped a person unlock their quicken backup file with help of Intuit by calling their support number. User forgot the password he created for the backup and when he tried to restore, he was unable to do it. Intuit was able to unlock that file for him using a master password...

schoen 11y ago
> How do we know they don't? Maybe someone can resolve this question by asking Google, examining Android source code, finding relevant online documentation, or even monitoring what a new Android device does on the network when setting up FDE. I don't feel like this should be a big insoluble mystery for the ages; it's a basic security property of a largely open-source OS that's one of the most popular in the world. We could even ask Micah Lee to do a follow-up article directly addressing other operating systems' FDE key management behavior.
- beeboop 11y ago
  You can't audit the firmware of the baseband processor, which is capable of sending the key to anyone, so there's not much point of auditing Android/asking Google. You cannot rely on any phone with a closed firmware baseband processor to be 100% secure. It might also come as a surprise to many than most every post-2008 Intel processor is similarly insecure: http://libreboot.org/faq/#intel http://libreboot.org/faq/#intel
  - simoncion 11y ago
    > You cannot rely on any phone with a closed firmware baseband processor to be 100% secure. That's not the question being asked. The question being asked is: "How do you know that the key for full disk encryption on Android is sent to Google?" Every technical person understands that any part of a system that has unrestricted read access to RAM can be used to thwart any FDE scheme. For the purposes of this conversation, it's not useful to talk about this. Doing so is like saying "One can be instantly vaporized by a nuclear bomb, therefore the question is irrelevant." in a conversation about whether aspirin or ibuprofen is safer for occasional relief of minor pain.
    - beeboop 11y ago
      My post does not answer that question and it wasn't trying to. The answer to that question is "We don't know". But suggesting that we do an audit of the code to find out doesn't seem productive, which is what I was responding to. That's a terrible analogy. It would be more accurate to compare this to aspirin and ibuprofen both sharing an unknown compound known to be capable of easily killing someone when the manufacturer wants it to, then suggesting we audit both aspirin and ibuprofen of their known compounds to make sure they don't have anything capable of killing someone. It doesn't really matter if it does, because you don't want to use aspirin or ibuprofen if you want to guarantee you won't die through someone's arbitrary decision, in the same way you wouldn't use Android on a phone if you want to guarantee security of your data.
      - schoen 11y ago