Hi @julesmazur, this feature seems to be implemented ("DNA-42872 Implement FIDO U2F" - the change log) in the latest Opera developer. If you want to check it out, you can enable it as follows: after you install the developer version, go to the address bar, paste opera:flags#cryptotoken, and press Enter, select "Enabled" from the drop-down, and press "Relaunch Now".