Extracting Qualcomm's KeyMaster Keys – Breaking Android Full Disk Encryption • Hacker News Board

Re: Extracting Qualcomm's KeyMaster Keys – Breaking Android Full Disk Encryption

#31

Post by LoSboccacc » Thu, Jun 30, 2016, 4:07 PM UTC

zeveb wrote: post #15

bognition wrote: post #4

Fascinating article, the more I learn about crypto and security the more obvious it becomes how hard this stuff is to get right.

You know, I'm not really all that certain that it's intellectually difficult to get crypto right; it feels more likely that it's organisationally and process-wise difficult to get crypto right. What I mean is that folks want to take an existing product and layer crypto atop it, when really they need to start from the crypto and built a product over it. They want to do things which are mathematically impossible (e.g.…

spot on with one minor nitpick: crypto is not hard to use (as in, relying on existing libraries/standards/practices) - doing, as in writing your own crypto, otoh...

Re: Extracting Qualcomm's KeyMaster Keys – Breaking Android Full Disk Encryption

#32

Post by userbinator » Thu, Jun 30, 2016, 4:19 PM UTC

bognition wrote: post #4

Fascinating article, the more I learn about crypto and security the more obvious it becomes how hard this stuff is to get right.

I think that might not be such a bad thing after all, since the flaws make it harder for companies to secure their products against the user, as they are apt to do. Something to ponder: would you rather live in a world of "perfect security" where encryption like this is unbreakable but so is DRM and other mechanisms of corporate/government control; or something closer to what we currently have, where "flaws" in encryption are periodically discovered but things like iOS jailbreaking and Android rooting still exist along with their associated freedoms?

Personally, I lean towards the latter.

https://www.gnu.org/philosophy/right-to-read.en.html

http://boingboing.net/2012/01/10/lockdown.html

http://boingboing.net/2012/08/23/civilwar.html

Re: Extracting Qualcomm's KeyMaster Keys – Breaking Android Full Disk Encryption

#33

Post by userbinator » Thu, Jun 30, 2016, 4:23 PM UTC

nxzero wrote: post #13

bognition wrote: post #4

Fascinating article, the more I learn about crypto and security the more obvious it becomes how hard this stuff is to get right.

There is no getting it "right" just less wrong; aka "perfect" security does not exist.

"perfect" security does not exist.

For that matter, I think what "perfect security" could be like is the world in Orwell's 1984 --- definitely not something I'd want existing either.

Re: Extracting Qualcomm's KeyMaster Keys – Breaking Android Full Disk Encryption

#34

Post by woumn » Thu, Jun 30, 2016, 4:23 PM UTC

If anyone is interested when the author talked about an overview of the iOS security measures, I created a more in-depth review that is an easy read and gives you a good over-view of the security architecture used. I'm happy to hear feedback if you enjoy it. The blog can be found at: https://woumn.wordpress.com/2016/05/02/security-principles-i...

Re: Extracting Qualcomm's KeyMaster Keys – Breaking Android Full Disk Encryption

#35

Post by koolba » Thu, Jun 30, 2016, 4:31 PM UTC

Full disk encryption (FDE) is a UX issue, not a technical one. You don't need a secure cryptographic processor, but the UX sucks without one.

A simple, working, FDE setup would be something like LUKS running at boot:

    1. Turn on phone
    2. Phone loads up initial bootstrap OS
    3. Phone prompts user for master key
    4. Master key is used to unlock volume
    5. Regular OS boot continues

If the master key has enough entropy, brute forcing it becomes impossible. The phone won't "disable" as there's no self-destructing component (i.e. "secure crypto chip") but that doesn't mean it can be cracked. Boil as many oceans as you'd like, you're not going to brute force 256 bits of entropy.

The UX problem is that the master key is a PITA to enter if it's long enough to be cryptographically secure. That's what a crypto chip is supposed to solve. A limited number of attempts with a shorter passphrase.

Re: Extracting Qualcomm's KeyMaster Keys – Breaking Android Full Disk Encryption

#36

Post by SixSigma » Thu, Jun 30, 2016, 4:33 PM UTC

userbinator wrote: post #32

bognition wrote: post #4

Fascinating article, the more I learn about crypto and security the more obvious it becomes how hard this stuff is to get right.

I think that might not be such a bad thing after all, since the flaws make it harder for companies to secure their products against the user, as they are apt to do. Something to ponder: would you rather live in a world of "perfect security" where encryption like this is unbreakable but so is DRM and other mechanisms of corporate/government control; or something closer to what we currently have, where "flaws" in encry…

I'd rather live in the unbreakable world because then the oppression is out in the open / forced.

People expect stuff to just turn up on Pirate bay, extraction tools etc.

Re: Extracting Qualcomm's KeyMaster Keys – Breaking Android Full Disk Encryption

#37

Post by userbinator » Thu, Jun 30, 2016, 4:35 PM UTC

lxgr wrote: post #23

devit wrote: post #16

It doesn't really break the encryption, as long as the password is strong enough to prevent brute forcing. Relying on a weak password and a "trusted computing" mechanism like this one from Qualcomm to prevent an attacker with physical access from brute forcing it is not really advisable. Using such a mechanism at all has downsides since it means that you lose the data if the mechanism or the entire device stops worki…

But how many Android users do you know that actually have a strong password? (Speaking of which: Google's decision to not allow strong encryption passwords together with short screen unlock PINs/patterns is not helping here. It's actually possible, but they don't expose the user interface to change them separately, probably for usability reasons.) Also, while I would agree as far as PCs are concerned, moving the eMMC…

moving the eMMC to a new phone's mainboard is probably also not a likely scenario.

Data recovery is, however, which is why I don't think one-sided promotion of ubiquitous hardware-locked-FDE is a good idea --- it becomes a tradeoff between others getting access to, and you losing access to, your data. Is it more important that this data be accessible by no one but you even if it means you might also lose access to it, or that you not lose access, even if it means others can access it? Hardware-locked FDE is suited only to the former case.

Re: Extracting Qualcomm's KeyMaster Keys – Breaking Android Full Disk Encryption

#38

Post by williamscales » Thu, Jun 30, 2016, 4:44 PM UTC

koolba wrote: post #35

Full disk encryption (FDE) is a UX issue, not a technical one. You don't need a secure cryptographic processor, but the UX sucks without one. A simple, working, FDE setup would be something like LUKS running at boot: 1. Turn on phone 2. Phone loads up initial bootstrap OS 3. Phone prompts user for master key 4. Master key is used to unlock volume 5. Regular OS boot continues If the master key has enough entropy, brut…

Wait, Android doesn't use LUKS?

Argh. Just give me a stinkin' smartphone that runs Linux. These are solved problems, people.

Re: Extracting Qualcomm's KeyMaster Keys – Breaking Android Full Disk Encryption

#39

Post by brainbrane » Thu, Jun 30, 2016, 4:46 PM UTC

LoSboccacc wrote: post #31

zeveb wrote: post #15

Earlier quoted context omitted.

You know, I'm not really all that certain that it's intellectually difficult to get crypto right; it feels more likely that it's organisationally and process-wise difficult to get crypto right. What I mean is that folks want to take an existing product and layer crypto atop it, when really they need to start from the crypto and built a product over it. They want to do things which are mathematically impossible (e.g.…

spot on with one minor nitpick: crypto is not hard to use (as in, relying on existing libraries/standards/practices) - doing, as in writing your own crypto, otoh...

Crypto is indeed hard to use.

https://www.nds.rub.de/media/nds/veroeffentlichungen/2011/10...

https://en.wikipedia.org/wiki/CRIME

Re: Extracting Qualcomm's KeyMaster Keys – Breaking Android Full Disk Encryption

#40

Post by Dylan16807 » Thu, Jun 30, 2016, 4:48 PM UTC

koolba wrote: post #35

Full disk encryption (FDE) is a UX issue, not a technical one. You don't need a secure cryptographic processor, but the UX sucks without one. A simple, working, FDE setup would be something like LUKS running at boot: 1. Turn on phone 2. Phone loads up initial bootstrap OS 3. Phone prompts user for master key 4. Master key is used to unlock volume 5. Regular OS boot continues If the master key has enough entropy, brut…

On the other hand, phones do not need to be rebooted often. And if I'm upgrading my OS the stupid thing is going to make me wait 20 minutes while it precompiles every app, so screw it I don't care if I have to spend 40 seconds inputting a password.