[Ar-Curunir]

There is no known result that says RH being true breaks modern encryption; if there was, the cryptanalysts would assume RH and try to break it anyway.

[IsTom]

Not RH being true, but that the proof itself would require discovering and proving something of high interest as an intermediate step.

[Ar-Curunir]

Perhaps, but it’s not clear that would be cryptographically relevant still.