Rotation Range-Coding (RRC) steganography achieves approximately 100% entropy utilization (99.98% on GPT-2) while maintaining zero KL divergence at every generative step, outperforming all prior provably-secure baselines: SparSamp at 96.76%, Discop w/ sort at 95.17%, iMEC at 71.44%. The rotation mechanism transforms the discrete uniform random variable into a continuous uniform at each step, preserving the original LM probability distribution exactly.
From 2026-yan-efficient-provably-secure — Efficient Provably Secure Linguistic Steganography via Range Coding
· §5.3, Table 1
· 2026
· arXiv preprint
Implications
LM-based steganographic channels can now achieve near-theoretical maximum covert bandwidth without detectable distribution shift — circumvention tools embedding configuration or keying material in LLM outputs can do so at nearly full entropy capacity.
The rotation mechanism is the key primitive: tools implementing covert channels via LM text should rotate the interval state at each step using a PRNG seeded from a shared key rather than directly encoding raw message bits.