Dynamics before diagnostics

The construction follows \[

code and Hamiltonian complete emission isometry
accessible channel and complement recovery and perturbation certificate.

The transfer channel is calculated, not selected by matching a radiation occupation spectrum.

Repeated quantum interactions provide an established Hamiltonian framework AttalPautrat. Here the finite collision sequence is the specified dynamics itself: no continuous-time limit or master-equation approximation is used. The collision-model overview Ciccarello supplies background only.

After identifying the radiation code, the accessible channel is a quantum erasure channel. This mechanism is standard Erasure. The contribution is a complete finite Hamiltonian-to-certificate application, including exact recovery constants, complete residual accounting, many-cell release, finite-time robustness, and access controls. No new erasure-channel mechanism or capacity theorem is claimed.

Hawk02-A records a conditional certification interface rather than the Hamiltonian instantiated here CheungHawk02A ({thm:main, thm:sequential}). Em03-E is a different Hamiltonian-derived finite emission model, with its own key and environmental accounting CheungEm03E. No early key is generated or assumed here.