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Comment by Dzugaru | Hacker News Reader

> If someone has physical access to your computer with secure documents present, it’s game over!

Err, why? Is AES encryption not sufficient? And the key is secure in my head - not something someone could steal.

So, why is this even a thing?

Unless you also want to perform the AES operations in your head, you have to rely on the hardware and software of your computer to perform them. An attacker could then replace the AES routine you use with one that stores a shadow copy of your key, or exfiltrates it over some covert channel.

What if the crypto side of things is remove-able and carry-able on your person? Or what if it could be subdermally implanted so you know no one can pick pocket you and replace it?

Just a thought.

> What if the crypto side of things is remove-able and carry-able on your person?

You might as well have the entire computer removable and portable.

And that's pretty much what ORWL is.

Well yeah, but this assumes I don't know the fact the physical access had place and proceed to enter the passphrase revealing the key unawaringly afterwards. If this is what "having physical access" means - then yes, I agree, game over, and ORWL solves it.

But if I know the attack took place (FBI broke into my house, the computer is locked in a safe etc.) - the data should be secure.

The key isn't in your head: you know the passphrase used to decrypt the key which is then kept in system memory. Techniques like the cold boot attack[0] or row hammer[1] can be used to retrieve the key and access your data. In the case of non-hardware-TPM secured encryption schemes the kernel or bootloader which must remain unencrypted for the system to boot can be backdoored to record the passphrase and/or the key.

0: https://en.wikipedia.org/wiki/Cold_boot_attack

1: https://en.wikipedia.org/wiki/Row_hammer

There is a section at the end of the page outlining mitigation techniques against these sorts of attacks. I'm not knowledgable enough to determine if these are sufficient measures but I just wanted to point it out since it sounds like you didn't see that.

They specifically cover cold boot attacks for example.

Right, OP was asking why having physical access to a "normal" machine means pwnage: cold boot is one of those ways. The ORWL page describes how they mitigate that.

Oh I see, thank you.

Yes, correct. We think we cover the cold boot vector. Here is a section from the product description. Security mesh physically protects DRAM from both freezing specific components and removal. Breaching the mesh will trigger reactive root key delete and system power down. Secure Microcontroller protects against chilling the full device - temps below -37℃ will trigger a tamper event, deleting root key and removing power from system. Link to the complete Product Description: https://www.orwl.org/wiki/index.php?title=File:ORWL_PRD_v0.6...

if someone has physical access to your computer with secure documents present, and then you use it again, it's game over.

Yes, physical access in most cases is a point of no GOOD return. That is why we emphasize so much on preventing this access. We have detailed the measures we have taken to prevent this here: https://www.orwl.org/wiki/index.php?title=File:ORWL_PRD_v0.6... Look at section: "ORWL Primary Key of Security or Root of Trust"

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