I'd expect "with reasonable certainty" to mean something different to pedantic lawyers/regulators than to pedantic cryptographers. Although perhaps an actual lawyer might suggest another phrase there, like "industry-standard measures" or something.
Yeah I think a lawyer would write something even more nebulous... We minimized the risk according with our assessment with industry standard measures in accordance with our threat model to a reasonable level of safety as defined in the international standards taking in account user experience and the requirements of our partners all in accordance with local and EU law...
