51–60 of 74 posts
Didn't know! After TC vanished with recommendation to use BL I had kept few files in direct Windows storage protected by BL. The more sensitive ones I still kept in Vera. Here my natural scepticism protected me lol. Guess turning on pre boot pw is next thing to do.
No big deal here. This attack looks like it's using a crusty old TPM 1.2 laptop, so encrypted parameters to the TPM aren't supported. Even with Win11 and TPM2.0 (required for Win11), encrypted parameters to the TPM would just slow down an attacker. You need to use pre-boot auth, like a PIN. Obviously, the TPM needs to have some kind of authentication to release the key, not just the default mode where Windows just ne…
TPM without PIN is the default configuration, so I'd consider it to be a big deal.
It is controllable through group policy, so orgs that care can force users into it.
TPM is insecure against physical attacks by design: https://gist.github.com/osy/45e612345376a65c56d0678834535166 The only secure implementation is called D-RTM which requires a level of chip, OEM, and OS support that's not done in practice.
There is nothing that is safe against physical attacks practically. You can always find a point where you can do a MITM attack as the communication channels between the TPM and anything else is almost always insecure.
Earlier quoted context omitted.
TPM without PIN is the default configuration, so I'd consider it to be a big deal.
The age old battle of security vs convenience. Most Linux distros don't force you into pre boot, PIN TPM encryption either. It is controllable through group policy, so orgs that care can force users into it.
Then I believe modern TPM communication is encrypted.
On too of that you want your laptop to support physical tampering resistance, which prevents both this (outdated) chip attack and freezing the RAM. When you then boot the laptop the master password is required. I would prefer it to throw off the PCR but hey, it works too.
I do wonder if you have 8GB of soldered RAM and 8GB on a stick, Windows keeps the key in the soldered part to increase difficulty stealing?
Earlier quoted context omitted.
It's a bit of a chicken-egg problem when the TPM is the root of trust for the entire system. Sure you can encrypt the data on the bus, but where do you store that key?
You use a Diffie-Hellman key exchange, signed by a cert stored in the CPU on one side and verified by the TPM on the other. CPUs already have such secret certs inside of them, for example for Intels' SGX. But as you can read in the article linked by /u/osy, the TPM ecosystem is a victim of design by committee where such things as a threat model are not a thing. They were focused on building a "generic security soluti…
because they want the threat model to be "what any customer who is going to buy this shit might have as a threat".
No big deal here. This attack looks like it's using a crusty old TPM 1.2 laptop, so encrypted parameters to the TPM aren't supported. Even with Win11 and TPM2.0 (required for Win11), encrypted parameters to the TPM would just slow down an attacker. You need to use pre-boot auth, like a PIN. Obviously, the TPM needs to have some kind of authentication to release the key, not just the default mode where Windows just ne…
TPM without PIN is the default configuration, so I'd consider it to be a big deal.
No big deal here. This attack looks like it's using a crusty old TPM 1.2 laptop, so encrypted parameters to the TPM aren't supported. Even with Win11 and TPM2.0 (required for Win11), encrypted parameters to the TPM would just slow down an attacker. You need to use pre-boot auth, like a PIN. Obviously, the TPM needs to have some kind of authentication to release the key, not just the default mode where Windows just ne…
No big deal here. This attack looks like it's using a crusty old TPM 1.2 laptop, so encrypted parameters to the TPM aren't supported. Even with Win11 and TPM2.0 (required for Win11), encrypted parameters to the TPM would just slow down an attacker. You need to use pre-boot auth, like a PIN. Obviously, the TPM needs to have some kind of authentication to release the key, not just the default mode where Windows just ne…
A PIN auth step eliminates the convenience value proposition of a TPM.
Selling passwordless authentication as a solution requiring a PIN just isn't recognizing that the PIN is now the password.