Key-space attacks against both key families, and the learned SNR sweep

check_family_enum.py now runs both attacks against both families. The
outsider ranks the L-1 Walsh rows; the insider, holding m_v, ranks the
L-1 products m_v .* m_r, which works because Walsh rows are closed
under the elementwise product and the per-block sign cancels in
m_u .* m_v. Both need a list to rank, and only the structured family
supplies one: the structured family falls at 0.905 from one frame at
10 dB and 0.990 from four, the refresh takes the outsider to 0.000 and
leaves the insider at 0.980, and the learned family gives 0.000
throughout.

exp_full.stage_N sweeps the learned family over the same SNR grid at
the same frame count as stage_A, so Fig. 2 can carry both families and
a reader can see what the key space costs at every SNR rather than at
one point.

check_consistency.py gains four assertions for the key-space
measurements and two for the learned sweep, 82 in all.

README: the assertion count was two rounds stale, and the figure map
omitted family_enum, cov_attack and maskdegen, whose CSVs back quoted
manuscript numbers.

README.md

@@ -58,6 +58,7 @@ 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 replot_security.py    # all figures from the CSVs
 python make_tables.py        # LaTeX rows of the result tables
@@ -98,6 +99,9 @@ Logarithms in an entropy or an information rate are base two.
 | 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` |
 
 ## Security scope