Mara stood at the edge of the dock, hands in her pockets, as police and journalists and scavengers converged. She had left no trace of her handiwork except for one small relic: a microtag on the mainframe—an artist’s signature that was half machine, half human. JUQ-565 pulsed, waiting.

where (h_d) is the d‑ary entropy function, (Q) is the QBER, and (\Delta) captures finite‑size corrections. With (d = 11), (Q = 2.2%), and (n = 10^9) bits, the bound yields a secret‑key fraction > 0.86, confirming unconditional secrecy.