Shift 1
Silent Night
Short-lived passes and a pass office that only renews them at the last moment.
Operation Silent Night
Sleigh Relay
The North Pole has outsourced Singapore's deliveries to a rushed relay, and Frostbyte has been tampering with it. Keep every sleigh moving until midnight.
How it works
- Sign in with your CSIT CTF access key and copy your launch key.
- Download the starter files, then write your own client in any language.
- Clear four shifts. Your client runs against the relay; notes for each new shift unlock when you clear the one before.
- Submit the flag the relay gives you after the last shift.
The four shifts
Shift 2
Chimney Rush
Deliveries bunch up on the same block, far too fast to take one at a time.
Shift 3
Blizzard
Sleighs with several stops, orders that change, and a relay clock restarted by guesswork.
Shift 4
Countdown
When the year turns over, every credential on the line rotates.
Hints
Silent Night
Your pass tells you when it runs out. Trust its clock, not yours.
Chimney Rush
Many deliveries at once need many hands, but only one of you should go back to the pass office.
Blizzard
Read every order again before you deliver it, and remember who signed for the last stop.
Countdown
At midnight the whole crew signs back on. Agree who does it, and do it once.