3 ms·

“if my password is complex enough” - fine for you, the average consumer chooses weak passwords, especially on mobile platforms. “what is to stop someone desold

by wepple 8y ago

“if my password is complex enough” - fine for you, the average consumer chooses weak passwords, especially on mobile platforms. “what is to stop someone desoldering the storage chip off my device and reading the data and bruteforcing that way?” - the key will be 128-bit, not bruteforcable in the next hundred years. The TEE contains that key, and can only be unlocked by giving it your user password, online. The remainder of your arguments seem to be “well it’s not perfect, so why bother?” Servers don’t get left on the subway or stolen. Modern PCs mostly do have forms of secure boot. I can’t speak for Android ecosystem, but users won’t get a popup on iPhone, a modded firmware will just not let the phone boot.

JoshuaAshton 8y ago
I agree, weak passwords are a big issue. I see your point about bruteforcing that key, however I was more talking about bruteforcing the password. Servers have been stolen in the past, and I am not just talking about a big rack server here. In Android, all you tend to get is an unlock symbol on the bootloader logo, or a warning triangle.
- wepple 8y ago
  I may be a bit confused. I apologize in advance if I misunderstood. With the desoldering the chip to read the data off, you’ll get an encrypted blob which is encrypted with a securely random 128-bit key, so it’s impossible to crack. the Key and the users password are embedded inside the TEE and cannot be read out - the TEE only provides an interface where you can supply a candidate password, and if you get it correct it’ll provide you the 128-bit key to decrypt your data. It has an internal delay and counter, and will destroy the key if you get the password wrong X number of times. So I’m not sure how you might go about being able to brute force the password, given you can only brute-force online, which is slow and will only give you a small number of attacks.

by wepple 8y ago

JoshuaAshton 8y ago

I agree, weak passwords are a big issue. I see your point about bruteforcing that key, however I was more talking about bruteforcing the password. Servers have been stolen in the past, and I am not just talking about a big rack server here. In Android, all you tend to get is an unlock symbol on the bootloader logo, or a warning triangle.

wepple 8y ago
I may be a bit confused. I apologize in advance if I misunderstood. With the desoldering the chip to read the data off, you’ll get an encrypted blob which is encrypted with a securely random 128-bit key, so it’s impossible to crack. the Key and the users password are embedded inside the TEE and cannot be read out - the TEE only provides an interface where you can supply a candidate password, and if you get it correct it’ll provide you the 128-bit key to decrypt your data. It has an internal delay and counter, and will destroy the key if you get the password wrong X number of times. So I’m not sure how you might go about being able to brute force the password, given you can only brute-force online, which is slow and will only give you a small number of attacks.