Files
TOIFAS/README.md
T
KiHoLee 138897aa8d Ship the learned-key pipeline, without which six figures cannot be rebuilt
The package was missing every script behind the KM (lrn.) curves and
both learned table rows: exp_learned's driver, the merge that folds the
learned rows into sec_compare.csv and refresh_summary.csv, and the
report that reads the learned numbers back. It was also missing
sec_keylen_perm.csv, so Fig. 3 could not be regenerated at all, and the
two diagnostics that answer why a fixed key beats a learned one here and
where a learned mask would win instead.

The learned artifacts themselves are regenerated. They were trained on
the cross-entropy alone, which drifts to disjoint sparse supports: 99
percent of each key's energy on about six of the 64 entries, so a digit
is decided over a sixth of its period and the key set is a choice of
support rather than a dense direction in R^L. They are now the
regularized keys of Section V-C, and check_consistency asserts which of
the two families the figures draw.

Verified from inside this repository: replot_security.py rebuilds all
seven result figures, make_tables.py reproduces both result tables, and
check_consistency.py passes every check that does not need the
manuscript.

The README now lists what ships. Its run list, layout and figure map had
none of the learned pipeline, named two tables the manuscript renders as
prose, and gave Fig. 3 no data file for its permutation curve.
2026-08-28 23:58:01 +09:00

141 lines
7.6 KiB
Markdown

# Keyed Masking for Secure Multi-User Semantic Communication
Reproducibility package for the manuscript *Mask-as-Key Secure Multiple
Access for Semantic Communications: Physical-Layer Encryption and
Jamming Robustness*, submitted to the IEEE Transactions on Information
Forensics and Security.
Every figure and table in the paper is regenerated from this
repository. Experiment scripts write CSV files to `data/` and never
draw; `replot_security.py` reads only `data/` and writes the figure PDFs
to `fig/`; `make_tables.py` prints the LaTeX rows of the result tables.
## Idea
Multi-user semantic communication superposes several users on one frame
and multiplies each user embedding by a distinct pattern so that the
receivers can separate them. This code treats that pattern as a secret
key. One keyed operation then encrypts each user against a receiver
without the key, separates the users, and spreads a jammer that does not
hold the key, at no extra bandwidth, power, or rate.
## Layout
```
code/
sse_lib.py transmit and receive core, channel, training, OMA reference
exp_full.py stages A-F and L: SNR sweep, key length, jamming across
schemes, key families, scheme comparison, attack difficulty
exp_kpa.py stage H: known-plaintext attack on the key
exp_refresh.py stage K: the key-refresh layer, invariance group
exp_permkpa.py permutation-key known-plaintext attack (Fig. 7)
check_cov_*.py ciphertext-only covariance-attack checks (referee M1)
exp_real_sec.py stage G: real BERT WordPiece token streams
verify_math.py closed-form checks V1-V11, PASS/FAIL and verify_math.csv
exp_learned.py every KM (lrn.) artifact, one function per stage
run_learned_reg.py runs those stages in order, sens before brute
merge_learned_rows.py folds the learned rows into the two table sources
report_learned.py every learned number beside its structured one
diag_whygap.py why a fixed key beats a learned one here
diag_jscc.py where a learned mask would win instead
replot_security.py every result figure, from data/ to fig/
make_tables.py LaTeX rows of every result table, from data/
feasibility_security.py early CPU-sized study, kept for the record
data/ CSV results, one file per stage
fig/ figure PDFs, regenerated by replot_security.py
```
## Reproducing
Requires Python 3, PyTorch, NumPy, and Matplotlib. The real-token stage
additionally needs `datasets` and `transformers`. A CUDA device is
recommended; the code falls back to CPU. Under Windows install PyTorch
in WSL, because the native Windows build does not load the CUDA
libraries.
```bash
python verify_math.py # closed-form verification, prints PASS/FAIL
python exp_full.py # stages A-F and L
python exp_kpa.py # known-plaintext attack
python exp_refresh.py # the key-refresh layer
python exp_real_sec.py # real token streams
python exp_permkpa.py # permutation-key known plaintext
python exp_infotheory.py # mutual information and equivocation
python exp_semantic.py # semantic-similarity leakage
python exp_users_csi.py # load and channel-estimate sweeps
python check_cov_attack.py # ciphertext-only covariance attack
python diag_maskdegen.py # learned-key support degeneracy
python check_family_enum.py # ciphertext-only enumeration of the key family
python run_learned_reg.py # every KM (lrn.) artifact, regularized keys
python merge_learned_rows.py # the learned rows of the two result tables
python replot_security.py # all figures from the CSVs
python make_tables.py # LaTeX rows of the result tables
```
The learned keys are the regularized ones of Section V-C, trained under
the two penalties rather than under the cross-entropy alone. Training on
the cross-entropy alone drifts to disjoint sparse supports, which is an
orthogonal slot allocation rather than a superposition; `diag_whygap.py`
measures that drift and `exp_learned.learned_model` says why the
regularized keys are the ones every figure draws.
Seeds are fixed: training 1, evaluation 777, attacker key guess
20260813, key recovery 4242, brute-force search 31, cross-scheme
comparison 11, key refresh 5150. Re-running reproduces the released CSV
files.
## Conventions
Flat Rayleigh fading, one gain per user per frame, with unit mean power.
A frame carries unit energy, so the SNR in decibels is the frame energy
over the total noise across all `d` real dimensions, and every scheme in
a comparison spends the same energy, bandwidth and rate. The
jamming-to-signal ratio is the jammer energy over the same frame energy.
Logarithms in an entropy or an information rate are base two.
## Figure and table map
| Artifact | Script | Data |
|---|---|---|
| Fig. 2 SER against SNR | `exp_full.stage_A`, `stage_N` | `sec_snr.csv`, `sec_snr_learned.csv` |
| Fig. 3 key length | `exp_full.stage_B`, `exp_learned.keylen`, `.keylen_perm` | `sec_keylen.csv`, `sec_keylen_learned.csv`, `sec_keylen_perm.csv` |
| Fig. 4 jamming (5 curves) | `exp_full.stage_C`, `stage_L`, `exp_learned.jamming` | `sec_jam_cmp.csv`, `sec_jam.csv`, `sec_jam_learned.csv` |
| Fig. 5 key sensitivity | `exp_full.stage_I`, `exp_learned.sens` | `sec_sens_cmp.csv`, `sec_sens_learned.csv` |
| Fig. 6 brute-force search | `exp_full.stage_I`, `stage_F`, `stage_J`, `exp_learned.brute` | `sec_brute_cmp.csv`, `sec_brute.csv`, `sec_brute_learned.csv` |
| Fig. 7 known-plaintext attack | `exp_kpa`, `exp_permkpa`, `exp_learned.kpa` | `kpa.csv`, `pkpa.csv`, `kpa_learned.csv` |
| Fig. 8 real token streams | `exp_real_sec`, `exp_learned.real` | `real_sec_ter.csv`, `real_sec_ter_learned.csv` |
| Scheme comparison table | `exp_full.stage_E`, `exp_learned.compare`, `merge_learned_rows` | `sec_compare.csv` |
| Key families (Sec. VI-G prose) | `exp_full.stage_D` | `sec_maskfam.csv`, `sec_regjam.csv` |
| Headline recovery (Sec. VI-H prose) | `exp_real_sec` | `real_sec_stats.json` |
| Key refresh table | `exp_refresh`, `exp_learned.refresh`, `merge_learned_rows` | `refresh_summary.csv`, `refresh_kpa.csv` |
| Information-theoretic leakage | `exp_infotheory` | `infotheory.csv` |
| Semantic similarity | `exp_semantic` | `semantic.csv` |
| Load and channel-estimate sweeps | `exp_users_csi` | `users.csv`, `csi.csv` |
| Permutation-variant check | `exp_full.stage_M` | `perm_variant.csv` |
Run one stage on its own with `python code/exp_full.py stage_B`, or the whole chain with no argument.
| Key-space attacks (Sec. VI-F) | `check_family_enum` | `family_enum.csv` |
| Covariance attack (Sec. IV) | `check_cov_attack` | `cov_attack.csv` |
| Learned-key degeneracy (Sec. VI-F) | `diag_maskdegen` | `maskdegen.csv` |
| Closed-form and symbolic checks | `verify_math` | `verify_math.csv` |
| Why a fixed key wins here (not in the paper) | `diag_whygap` | `whygap.csv` |
| Where a learned mask would win (not in the paper) | `diag_jscc` | `jscc.csv` |
## Security scope
The analysis covers an adversary that observes transmitted frames. The
masking is linear, so an adversary that also learns the indices some
frames carried recovers the key from a few frames, which `exp_kpa.py`
measures. The key must therefore be refreshed per coherence block from a shared
seed. `exp_refresh.py` implements that layer and shows why it has to
draw from the transformations that leave the decision statistic
invariant: a refresh that installs fresh orthogonal keys instead costs
the legitimate users a factor of 2.3, while the invariant
refresh costs nothing and raises the per-block key from 23.8 to 364.6
bits.
## License
MIT for the code. The AG News data and the language-model tokenizer are
obtained from their own sources under their own terms.