Story code: ST-001342
Part 2: The Cryptographic Trail
By mid-afternoon, Danny Vance sat at the office terminal, his boots tapping rapidly against the metal floor. Clara stood near the vault entrance, her arms crossed, watching her brother’s movements. When I displayed the digital timeline on the main wall screen, Danny did not look at the data. He kept his eyes on his palms, rubbing his thumbs together. The station’s heavy ore processors rumbled in the distance, a low vibration that rattled the diagnostic tools on the workbench. The fluorescent lights overhead flickered, casting long shadows across the metal walls of the Vance Mining Contract Office.
‘I was in my quarters by midnight,’ Danny said, his voice rising slightly. He kept shifting in his seat, refusing to meet Clara’s steady gaze. ‘The keycard was in my jacket. If Thorne or anyone else used it, they must have copied the signal while I was at the docks yesterday. You know how easy it is to skim a card in the crowded transit tubes near the lower berths.’
I pointed to the secondary log line on the screen. ‘The physical keycard was not cloned, Danny. The reader recorded a physical contact swipe, including the specific micro-wear patterns unique to the chip on your card. It was swiped at the outer door at 03:12, and then at the vault door at 03:14. A cloned card leaves a different magnetic signature because it uses a standard rewriteable band. This was your actual, physical card, and it was used by someone who had the exact physical object in their hand.’
Danny stood up, pacing the narrow space between the terminal and the metal wall. ‘The logs are incorrect. Or someone took the card while I slept and returned it. I didn’t give Thorne access to the vault. Why would I let him anywhere near the claim token?’
Marcus Thorne walked back into the office twenty minutes later, carrying a hard-copy shipping manifest. He laid the pages on the desk, his movements deliberate. He tapped the paper with his index finger, looking at Clara. ‘If there is a dispute about the claim’s security, I need to know now. The buyers in the inner belt will not hold their offers if the Vance claim is flagged for an internal family investigation. We need to clear this batch before the station authorities freeze the sector.’
Clara did not touch the manifest. She remained standing near the vault, her posture rigid. ‘The claim is not in dispute, Marcus. But my investigator is reviewing the security access history. We are not signing any shipping authorizations until we know why the vault was accessed.’
Thorne looked at Danny, then back to Clara. ‘You are looking for problems where there are none. The token is in the vault. The shipments are ready. Let’s sign the authorization and clear the deck. Danny, tell her we don’t have time for this.’
I adjusted the terminal display, pulling up the station’s internal corridor log. It showed no record of Danny Vance leaving his quarters during the early morning hours, proving he had not physically walked to the office to use his card. However, the external corridor camera near the contract office registered a figure matching Marcus Thorne’s height and gait walking down the hall toward the office entrance at 03:10. The figure did not wait for an occupant, stepping directly inside as the door lock disengaged.
Danny avoided looking at Clara, his breathing shallow as he leaned against the desk. He picked up a stylus and turned it over and over in his fingers, his eyes fixed on the metal floor.
I zoomed in on the terminal transaction record from three days prior. A new data point emerged. A local network transmission had sent the master encryption keys of Danny’s card directly to Thorne’s personal comms address, originating from Danny’s own terminal. The file transfer was labeled as a routine system backup, but the recipient address was unmistakable.