Any educated guesses?
Any educated guesses?
edit: As it is also required to have an ID card this should cover 100% of the population of Belgium.
In Czech Republic chip ID is optional and you have to pay (~20EUR) for the chip itself. As it does not have any meaningful purpose that is legal (loading your own certificate onto the card is technically possible but explicitly outlawed) even the local authorities issuing IDs will advise you that you don't want chip ID.
In contrast to that in the above mentioned countries I've seen state issued smartcards (regardless of whether they are EU-wide ID or just additional smartcard) used for useful purposes (eg. to submit VAT returns online, which is something that in .cz you can do with any PKCS#11 token of you choosing or by using state-run OAuth-ish ID provider)
I cannot provide any citation for that, but I believe that the EU regulations related to digital signatures require that the private key to not be available to the state, which implies either on-card generation or same process as is used by commercial CAs (which is the case in .cz, where you can choose from three or so CAs which are at least notionally commercial entities)
Actually signing is performed differently and since this summer they switched to a cloud signing process where you don't have access to your key. You cannot get a certificate for a key on the card anymore. Not that anyone actually used that feature.
Edit: otherwise you confirm my suspicion that essentially nobody uses the chip on ID cards outside of Estonia (Slovakia is mentioned due to their recent massive rollout of chip IDs inspired by Estonia, but I assume that actual usefullnes is nil)
Googling suggests that they might be another user of the ~~infected~~ infineon SLE78 platform.