Updated PRF Compatibility Section

[gkatrakazas]

This update introduces refined transport names for clarity and adds a detailed compatibility table for each operating system and browser combination.

In reference to issue #81

PRF Compatibility Support by Operating System and Latest Browser Versions

Operating System	Chrome (v116+)	Edge	Firefox	Opera	Safari	Brave
Linux	✔	-	❌	-		✔
Windows	✔	✔	❌	✔		✔
MacOS	✔	✔	❌	✔	❌	✔
Android	✔	✔	❌	✔		✔
iOS	❌	❌	❌	❌	❌	❌

PRF Compatibility Scenarios

Operating System	Authenticator	Transport	PRF Compatibility
Linux	YubiKey	USB	✔
Linux	Android	Hybrid	✔
Linux	iOS	Hybrid	❌
Windows	YubiKey	USB	✔
Windows	Android	Hybrid	✔
Windows	iOS	Hybrid	❌
Windows	Windows	Internal	❌
MacOS	YubiKey	USB	✔
MacOS	MacOS	Internal	❌
MacOS	Android	Hybrid	✔
MacOS	iOS	Hybrid	❌
Android	Android	Internal	✔
iOS	iOS	Internal	❌
iOS	YubiKey	NFC	❌

Feel free to provide suggestions or improvements.

[joostd]

As an authenticator, any FIDO security key should work, as long as it supports the CTAP hmac-secret extension.
I tested with a Solo key (v1). Perhaps we should also maintain a table with verified authenticators?

See also https://opotonniee.github.io/fido-mds-explorer/ for entries where metadataStatement.authenticatorGetInfo.extensions includes hmac-secret.

[gkatrakazas]

If I understand correctly, we should rename the 'YubiKey' to 'Security Key' to make it more inclusive and reflective of various compatible security key models.

As for the new table for verified authenticators, are you suggesting that we should list different security key models that have been tested? This would differ from the current table, which display prf compatibility by OS and authenticator category.

[joostd]

Perhaps use the term fido security key for now, and add a comment that any security key should work, provided it supports hmac-secret.

We could also refer to
https://opotonniee.github.io/fido-mds-explorer/
where hmac-secret support is listed under metadataStatement > authenticatorGetInfo > extensions

[joostd]

Looks good to me!