Re: [Rats] FIDO TPM attestation

[Laurence Lundblade <[e-mail]>]

> On Nov 14, 2019, at 1:46 AM, Fuchs, Andreas <[e-mail]> wrote:
> 
> The FIDO code running inside a TEE is not standardized (to the level of TPM) and most certainly not CC-evaluated.


That’s not true.

The FIDO L3 and L3+ Certification program <https://fidoalliance.org/certification/authenticator-certification-levels/authenticator-level-3/> is CC (Common Criteria) based (AVA_VAN.3 and AVA_VAN.4).  

Many FIDO authenticators run on secure elements which provides roughly equivalent security to a TPM, however since the full authenticator protocol runs on the turing-complete secure element the full FIDO protocol is secured, not just the key storage. Here’s one <https://www.yubico.com/products/yubikey-hardware/yubikey%20neo/>.

Global Platform offers a CC-based certification program for TEE’s <https://www.commoncriteriaportal.org/files/ppfiles/anssi-profil_PP-2014_01.pdf>. FIDO is working on a certification program that will make use of that.

BSI has published a CC-based protection profile for FIDO <https://www.commoncriteriaportal.org/files/ppfiles/pp0096a_pdf.pdf>.

Android Keystore’s now supports StrongBox <https://proandroiddev.com/android-keystore-what-is-the-difference-between-strongbox-and-hardware-backed-keys-4c276ea78fd0>, which puts the keys in a secure element.

Qualcomm’s Snapdragon mobile phone chip has a secure-element like subsystem <https://www.qualcomm.com/news/releases/2019/06/25/qualcomm-snapdragon-855-becomes-first-mobile-soc-receive-smart-card> (not the TEE) that is CC-certified.

TEE and TEE-like offerings are stronger than they used to be, particular by supporting memory encryption.

Turing complete security products come in a range of security levels all the way up the security level offered by a TPM. EAT implementations can be just as secure and certified as TPM attestation.

LL