aes128_feistel.cuh File Reference

Small-domain PRP via 4-round Feistel network with AES-128 round function and cycle-walking. More...

#include <fss/prp.cuh>
#include <cuda_runtime.h>
#include <cassert>
#include <openssl/evp.h>
#include <openssl/aes.h>

Classes
class	fss::prp::Aes128Feistel
	Small-domain AES-128 Feistel PRP for Cuckoo hashing. More...

Detailed Description

Small-domain PRP via 4-round Feistel network with AES-128 round function and cycle-walking.

Copyright

Apache License, Version 2.0. Copyright (C) 2026 Yulong Ming i@myl.nosp@m.7.or.nosp@m.g.

Author

Yulong Ming i@myl.nosp@m.7.or.nosp@m.g

Given a target domain [0, domain), the construction:

1. Computes b = ceil(log2(domain)) and half = ceil(b / 2).
2. Runs a 4-round balanced Feistel on (2 * half)-bit values, using AES-128 as the PRF for each round (with per-round key tweaking).
3. Cycle-walks: if the Feistel output >= domain, re-applies the Feistel until it lands in [0, domain). Expected iterations < 4 because 2^(2*half) < 4 * domain.

Security: 4-round Luby-Rackoff gives CCA-secure PRP. Cycle-walking preserves the permutation property (Black & Rogaway, 2002).