That’s what I had assumed too, but the technical feasibility to do so doesn’t necessarily mean that SecKeyCreateWithData will act as expected. I had initially assumed it was creating a key with the specified representation but I’ve tried creating it with bogus NSData and it still yields new keys so I now suspect that it simply generates new ones. Intuitively, the API called by CreateWithData would presumably be a key creation API where it specifies the additional data to use with the key (e.g., an existing x963 representation) but evidently this value must be ignored by the Secure Enclave because it does not appear to generate compatible keys. So, whilst I suspect it is technically feasible to convert between the representation, I am back to thinking that there is not actually a way to do it with available APIs. Of course, this is all just my understanding.

Having done some experimentation it seems that SecKeyCreateWithData simply creates a new key when kSecAttrTokenID: kSecAttrTokenIDSecureEnclave is passed - presumably because it causes the Secure Enclave to generate a new key and the Secure Enclave ignores the associated data.

Thanks Quinn! I'm a little baffled as I'm certain I tried this already but it does indeed work now, and even when I re-add the code to do biometrics in a Playground App. I guess it was just starting over with a minimal recreation...

I don't think that command, as written, would have been able to cause that. Are you sure you didn't do something like rm -rf . /anaconda3 or rm -rf ~ /anaconda3 (note the spaces)? (EDIT: note that / is a forward slash, /) That space would have meant remove everything in the home directory and anaconda3 (assuming in the former case, that you ran the command in your home directory, which is usually the default location to run a shell command from). As an aside, I'm new here but I don't think this is the best place to ask a question like this as it's intended for software development questions (see Quinn's Top Ten DevForums Tips). You'd probably be better off asking either on the Apple Support Communities or https://apple.stackexchange.com.

You should have the option to reply in the "App Review" page on App Store connect. I would simply reply there and state, as you did here, that you are currently only offering a free plan. If you don't need it right now, you could simply remove the "In-App Purchase" capability/entitlement and add it back in a subsequent build when you submit the version with paid plans.