Honest question: What makes you think you can't mitigate? A̶ ̶t̶y̶p̶e̶s̶a̶f̶e̶ ̶c̶r̶y̶p̶t̶o̶ ̶t̶h̶a̶t̶ ̶m̶e̶a̶s̶u̶r̶e̶s̶ ̶i̶t̶s̶ ̶e̶x̶e̶c̶u̶t̶i̶o̶n̶ ̶t̶i̶m̶e̶ ̶a̶p̶p̶e̶n̶d̶e̶d̶ ̶w̶i̶t̶h̶ ̶a̶ ̶f̶i̶n̶a̶l̶ ̶d̶e̶l̶a̶y̶ ̶t̶i̶m̶e̶ ̶r̶e̶a̶d̶ ̶f̶r̶o̶m̶ ̶/̶d̶e̶v̶/̶u̶r̶a̶n̶d̶o̶m̶ ̶c̶a̶n̶ ̶s̶t̶i̶l̶l̶ ̶b̶e̶ ̶i̶d̶i̶o̶m̶a̶t̶i̶c̶.̶ It has to be monadic, that is for sure but abstracting a crypto algorithm as IO is actually treating it as a device which sounds like a safe metaphor.
Edit: Whoah, why the hate? :(