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ExpKorzhCow ​

Tier B: Korzh et al. 2015, COW over 307 km of ultra-low-loss fibre

11/11 passed in 1ms

TestWhat it doesResult
test_korzh_ceilingTheir secret rates sit at 12.1% (307 km) to 45.0% (203 km) of the per-click ceiling; declared miss: against their sifted block the ceiling reads 0.672 and 0.689 at 203 and 307 km.✅ pass
test_korzh_darkBackground-free the model is flat at 1.1537%; halving their dark column puts 307 km at 2.36% and doubling it at 5.63%, both excluded by their 3.5%.✅ pass
test_korzh_deadModel click rate plus measured dark counts uses 61.9% of the 1/dead_time ceiling at 104 km, falling to 0.32% at 307 km.✅ pass
test_korzh_formcow_rate is 1−h2(ephase)−fh2(ebit), above Korzh's Branciard-Gisin-Scarani form by exactly Q(1−h2(ephase)), 9.9% at 307 km.✅ pass
test_korzh_nearDeclared miss: 104 km reads 1.526% against their 2.40%, needing an afterpulse-like background of 1.84% of the count rate, against 0.63% at 256 km and -0.11% at 153 km.✅ pass
test_korzh_penaltyTheir Eq. (3) fraction less the 7 sqrt(n_cpp log2 1/beta) term reproduces f_sec to 0.05% at 104 km (block 1.97e7) and misses by 38% at 307 km (6.6e5), the unmodelled Eq. (2) visibility deviation.✅ pass
test_korzh_qberFitted at 203 and 307 km, the model gives 1.555% at 153 km against their 1.5% and 1.700% at 256 km against their 2.0%.✅ pass
test_korzh_receiverThe fitted factor over their 20% efficiency needs a 0.9331 data-line share, a lower bound since the 20% is stated below 150 K; refitting at 153 and 307 km moves the factor 2.8% and the baseline 5.8%.✅ pass
test_korzh_secretqkd's asymptotic COW fraction on the Branciard-Gisin-Scarani phase error exceeds their finite-key f_sec at every distance, 1.065 times at 104 km and 2.133 at 307 km.✅ pass
test_korzh_spanThe loss column exceeds bare 0.160 dB/km fibre by 0.26 dB at 104 km rising to 2.78 dB at 307 km, 0.1625 to 0.1691 dB/km end to end.✅ pass
test_korzh_tableSource defect: r_sec = n_cpp f_sec / t_cpp holds to 1.2% at 104, 203 and 307 km but reads 0.810 at 153 km and 0.446 at 256 km.✅ pass