Marcin Pawlowski e9b79ce90a

blend: attribution evidence at the reported scale, and a figure for the timing study ...

Two gaps left by the previous review.

Section 3.4 quoted the attribution bracket at N=20,000 while the only committed
evidence carrying those columns was the timing run at N=2,000, so a reader diffing
report against data saw different numbers for the same quantity. Added
configs/attribution.yaml and a make target: it records both bounds and the graph
hop distance at the reported scale, cheaply, since the adversary and
deanonymization metrics are closed-form and the hop distance is a property of the
topology. It reproduces the section exactly -- L = 2.58 and neighbourhood
confidence 0.640 at degree 8, f_adv 0.2.

It also surfaces a result the smaller run could not: degree cuts both ways. A
sparser graph has longer routes, so it offers the adversary more upstream places
to see the message -- L is 4.18 at degree 4 against 1.93 at degree 16, lifting
neighbourhood confidence from 0.61 to 0.72. The low diameter that makes
propagation fast also starves the adversary, one of the few places where raising
the degree helps anonymity rather than hurting it.

Section 3.11 was the only section without a figure. Fig 25 plots MAP success
against the effective anonymity set for both release designs: the dashed sets
separate far faster than the solid best-guess curves, which is the whole argument
for not trusting perplexity alone.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

2026-08-06 18:00:02 +02:00

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