Cellebrite’s internal processes would still be subject to discovery. Defendants have a right to show that the extraction process was flawed otherwise it could lead to wrongful convictions.
Secret / Magic / black box processes can’t generate admissible evidence in criminal proceedings in the US.
Defendants do have that right, and in practice Cellebrite has a handful of expert witnesses they will send out to answer the courts questions. In this case there is no "black box" because the Cellebrite has been litigated previously and is known to the court.
If you want to challenge the reliability or accuracy of the process you need to have some basis to show the judge there is a thread to pull on and it isn't just a fishing expedition.
For an idea of how courts handle this, look at breathalyzers. People occasionally get the bright idea to ask to inspect the source code of the machine, and it is routinely denied because it is not in the possession of the prosecution. https://digitalcommons.law.uw.edu/cgi/viewcontent.cgi?articl...
Generally, no. As I mentioned up thread you need to have some basis to show the court there is some chance you'll change the outcome of your case if you are granted access to the source code. For example if a blood draw at the hospital yielded wildly different results, or the machine froze up multiple times during the test.
Speed cameras are usually tested and certified by an independent third party. With proper cause, there's probably a pretty good chance you could get an expert to review the design files after signing an NDA.
Traffic typically has lower standards because it is in county court with a clown presiding as magistrate. It becomes too expensive to appeal and if you aren't an attorney you will immediately lose because they know you are unlikely to again appeal.
Secret / Magic / black box processes can’t generate admissible evidence in criminal proceedings in the US.