If your password isn't strong, now is a good time to fix this - the risk involved with using a weak password generally transcends Chrome OS and affects other places that store sensitive data.įor hardware-backed encryption keys and Verified Access, mitigations are technically infeasible without losing the hardware binding, and thus breaking the feature. This measure guarantees adequate protection of encrypted user data for users that use strong passwords. Users were automatically upgraded to the new scheme behind the scenes without user-observable effects.
In Chrome OS M60, we strengthened Chrome OS user data protection using the scrypt password hashing scheme to act as a second line of defense even in case the brute-force protection afforded by the TPM is lost. Attackers can exploit the vulnerability to break an "Attestation Identity Key", which allows them to impersonate a legit device from an endpoint of their choice.
TPM-generated RSA keys (bit size 2048) are used in the certification process. You can check key sizes for certificates backed by TPM keys at chrome://settings/certificates.Ĭhrome OS Verified Access allows network services to verify client device integrity and identity. The bit sizes supported by Chrome OS for TPM-backed keys are 1024 or 2048. The bit size of generated and imported keys depends on parameters. The vulnerability allows attackers to determine the private key. These keys are typically accompanied by a certificate and then used in network authentication, such as WPA2-EAP, HTTPS client authentication, etc. Chrome OS allows users to generate and import RSA keys that are protected by the TPM so the main OS can't access the private key. Hardware-backed encryption keys / certificates. However, note that off-device brute-force attacks are only advantageous against strong passwords - weak passwords are still less expensive to brute-force against the TPM regardless of whether it runs vulnerable firmware or not. The vulnerability allows the attacker to brute-force the encryption key (bit size 2048) off-device. The page Protecting Cached User Data describes this in more detail. Slowing down brute-force attacks against encrypted user data. Impacted featuresĬhrome OS relies on TPM-generated RSA keys for a number of features: To summarize: There exists a practical attack against TPM-generated RSA keys, but it doesn't allow large-scale exploitation of Chrome OS devices. At the current point in time, it means TPM-generated RSA keys can't be broken at large scale, but targeted attacks are possible. Note that this figure might drop as more researchers look at the attack. Currently known exploits are computationally expensive specifically, for RSA keys of bit size 2048, the researchers give an estimate of 140.8 CPU years to break a single key. The researchers who found the vulnerability have published high-level information here. There is a bug in certain Infineon TPM firmware versions which results in RSA keys generated by the TPM being vulnerable to an attack that allows to recover the private half of the RSA key from just the public key.
#Samsung flow tpm update
6.7 Subsequent TPM firmware update prompt.
#Samsung flow tpm install
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