Whatever Happened to the One-Time Pad?

A banker published the first one-time pad in 1882 and told readers to erase the numbers after use. Shannon proved in 1949 that it's mathematically unbreakable. So why has almost every attempt to actually use one failed? This episode follows the pad's real lineage — Vernam's repeating tape, the Soviet duplicate pages that cracked Venona, SIGSALY's fifty tons of vinyl key records, the Moscow-Washington teletype, and Ana Montes's diskettes — to the uncomfortable conclusion that the cipher was never the weak part. Then we ask what replaced it: fill devices that courier a few hundred bits of AES key instead of a pad as long as everything you'll ever say, and quantum key distribution, which reproduces the physics but not necessarily the discipline.

Episode 6152 — myweirdprompts.com/n/6152 (permanent short link: myweirdprompts.com/911740)