eprint.iacr.orgpaper

Master-Key Recovery from Internal Activation Leakage in ReLU Realizations of Camellia

The paper builds explicit ReLU neural-network realizations of Camellia-128/192/256 from exact Boolean gates, S-box selectors and bit permutations, and reports known-answer-test agreement for Camellia-128. It shows that whitening and round-key quantities leaked from internal activations determine the master key through public key-schedule identities. Under a synthetic internal-oracle model, symmetric real-valued perturbations recover subkey bits with 128 queries (Camellia-128) or 256 (Camellia-256). Camellia-192 is handled by deterministic key-schedule inversion from direct access to round keys. All 3,000 trials (1,000 keys per variant) recovered the key exactly. The authors state this is not a plaintext/ciphertext-only attack on standard Camellia.