This story serves double-duty. For Flash! Friday vol. 3-18, the prompt is to include a spy, along with the shown CC2.0 photo by Foto Michel. For day ten of the A-to-Z challenge, J is for Jupiter brain, a megastructure the size of Jupiter, designed for tremendous computational capabilities.
I was nervous about my first visit to the oracle, but I had a mission. With only a few coins, I entered the noisy bazaar.
“Spare some change?” The panhandler shook his cup at me, so I tossed him some platinum. “Jupiter happily helps he who helps the needy. You seek wisdom?”
“How can I decrypt the Zoephage communications?” The Geminga Confederation had not known war in over two centuries when the Zoephages turned three border worlds into grey goo. Now it fell upon the Spy Corps to discover some weakness in our nanoscale enemy. A trillion human lives, from Earth to Antares, depended on us.
“Their communications are encrypted by one-time pad.” My heart sank. OTP encryption was uncrackable without the random shared key. As I turned to leave, I gave him my remaining coins.
“Thank you kindly for sharing with a random stranger,” said the hooded Oracle of Jupiter.
Suddenly I realized: the swarms of Zoephages needed to share a random key across a dozen parsecs. The most accessible source of randomness was Cosmic Microwave Background fluctuations. And the Spy Corps kept detailed recordings of the CMB. Smiling, I rushed to purchase my ticket back to headquarters. Random does not mean secret.