You can flash the firmware without using DTS (Dasharo Tools Suite), you can download the ROM for your hardware and flash it from any Linux livecd using flashrom, or can take it one step further and compile coreboot ROM yourself.
The DES (Dasharo Entry Subscription) is really only needed if you want to PXE network boot the DTS image to update the firmware via network, this is an option in the boot device selection menu, in which case you do need to use the subscription info it’s a subscription only feature.
You can use Dasharo just fine without using the DES, on Qubes OS it’s just easier to update the firmware with DES.
As explained in the discussion on the Nitrokey forum, we need email to deliver information about update availability. No other information is shared with us from our partners. I’m not sure if the email is personal data. I guess it depends on the jurisdiction and the email itself.
@renehoj, things changed a little bit because now we started releasing DES-only binaries. For example, v1.1.2 binaries are available only to subscribers. Of course, the source code is on the GitHub repository. As explained during DUG #2, we have no issues with skilled community members compiling the code and using the binaries, but on the other side, we need sustainability of this product, because of that we decided to create the subscription and experiment with adding more value then you can typically get with coreboot by compiling it your self (hence newsletter, documentation, hashes, signatures, tests, special binary releases etc.). All that with the hope we can have long-term support for this product and validate some new business models for open-source firmware.