Establishes tight indistinguishability bounds for sum of permutations in classical and quantum settings using Fourier analysis, with applications to PRP-to-PRF conversion and variable-output constructions like LXoP.

Establishes tight indistinguishability bounds for sum of permutations in classical and quantum settings using Fourier analysis, with applications to PRP-to-PRF conversion and variable-output constructions like LXoP.