I would be surprised if there was any crypto where not any output bit depended on any input bit (of course it depends on what precisely one means by "depends up

I would be surprised if there was any crypto where not any output bit depended on any input bit (of course it depends on what precisely one means by "depends upon"). Otherwise, couldn't the search-space be partitioned? See also: Shannon's confusion and diffusion principle [1], as well as the avalanche effect [2]. [1] https://en.wikipedia.org/wiki/Confusion_and_diffusion https://en.wikipedia.org/wiki/Confusion_and_diffusion [2] https://en.wikipedia.org/wiki/Avalanche_effect https://en.wikipedia.org/wiki/Avalanche_effect