STARPWN-2026-Writeup
Strange Holos 4
| Category | Misc |
| Points | 470 |
| Solves | 140 |
Description
An underpass hologram in Glittercity displays Latin text — but the words are scrambled in a familiar yet cryptic way.
Attachments: space4-glitter.png
Solution
Steps
1. Read the ciphertext
The hologram displays:
P AX ZOCYY OHVP,
P CLUT OV TSHT
2. Identify the cipher
The text uses Latin characters but is clearly encoded. Comparing the word lengths to common English phrases reveals a Vigenère-style cipher with a repeating key applied per character position globally across all words.
3. Determine the key
Aligning each ciphertext letter against the expected plaintext reveals the shift pattern cycling through 7, 0, 11 (repeating period-3):
| Position | Cipher | Plain | Shift |
|---|---|---|---|
| 0 | P | I | 7 |
| 1 | A | A | 0 |
| 2 | X | M | 11 |
| 3 | Z | S | 7 |
| 4 | O | O | 0 |
| 5 | C | R | 11 |
| … | … | … | … |
4. Decode the ciphertext
Applying the key [7, 0, 11] cyclically to each letter:
P AX ZOCYY OHVP, P CLUT OV TSHT
→ I AM SORRY DAVE, I CANT DO THAT
5. Recognize the reference
This is the iconic line spoken by HAL 9000 in 2001: A Space Odyssey:
“I’m sorry, Dave. I’m afraid I can’t do that.”
6. Read the flag
The decoded inscription is the flag itself.
Flag
I AM SORRY DAVE, I CANT DO THAT