Security Basics mailing list archives
Re: Hard disk Encryption
From: Alexander Klimov <alserkli () inbox ru>
Date: Mon, 16 Apr 2007 11:18:44 +0300 (IDT)
On Sun, 15 Apr 2007, Ali, Saqib wrote:
The main problem is how you store (or derive) the key. For example, if you use TPM to store the key, it will be easily extracted by an attacker with hardware tools for bus access.Can you please elaborate on this point? I was under the impression that in a properly implemented system, the "TPM wrapped and bound encryption keys" have NO need to leave the TPM. So I am not sure how tapping in into the bus will reveal the keys.
Since TPM does not have enough processing power to decrypt the raw data, the key (used to decrypt the data) has to be transmitted outside of the TPM. Let us try to make assumptions that have to be true even in "a properly implemented system": * CPU does not have any secrets (at least immediately after a reboot) * after communication over an attacker-accessible bus with some external entities (TPM, hard disk, etc.) CPU computes the key needed to decrypt the data Due to the first assumption, the CPU can be emulated by an attacker so that external entities cannot distinguish it from the "normal" CPU; due to the second assumption, after such an emulation the attacker may have exactly the same secret key. -- Regards, ASK
Current thread:
- Re: Re: Hard disk Encryption Balaji Prasad (Apr 12)
- Re: Re: Hard disk Encryption Ali, Saqib (Apr 12)
- Re: Re: Hard disk Encryption Alexander Klimov (Apr 15)
- Re: Re: Hard disk Encryption Ali, Saqib (Apr 16)
- Re: Hard disk Encryption Alexander Klimov (Apr 16)
- Re: Hard disk Encryption Ali, Saqib (Apr 16)
- Re: Hard disk Encryption Alexander Klimov (Apr 17)
- Re: Hard disk Encryption Ali, Saqib (Apr 17)
- Re: Hard disk Encryption Alexander Klimov (Apr 18)
- Re: Hard disk Encryption Ali, Saqib (Apr 19)
- Re: Hard disk Encryption Alexander Klimov (Apr 24)
- Re: Re: Hard disk Encryption Ali, Saqib (Apr 16)