asepharyana
7a6e717c28
- Deleted all previous dummy docs (defcon-quals-2024, infra/cloudflare-525, debugging/websocket-timeout, template, docs/*, notes/*, research/*) - Added 14 Gemastik warmup writeups covering encoding, stego, web, pwn, crypto - ch13: RSA small factors; ch14: RSA special integers via paper-search (GCD with paper appendix primes) - All flags recovered and documented with solution methods
30 lines
654 B
Markdown
30 lines
654 B
Markdown
---
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title: "Julius — ROT13 Caesar Cipher"
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event: "GEMASTIK 2026 Warmup"
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challenge: "Julius"
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category: "crypto"
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points: 500
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difficulty: "easy"
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flag: "GEMASTIK19{caesar_r0t_th1rt33n_klasik}"
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---
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# Julius (500 pts) — Caesar / ROT13
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**File:** `chall.txt` → `TRZNFGVX19{pnrfne_e0g_gu1eg33a_xynfvx}`
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Caesar cipher dengan pergeseran paling populer di internet = **ROT13** (geser 13).
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`TRZNFGVX19` → `GEMASTIK19`, dst.
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```python
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import codecs
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s = "TRZNFGVX19{pnrfne_e0g_gu1eg33a_xynfvx}"
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flag = codecs.encode(s, "rot_13")
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print(f"Flag: {flag}")
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# Output: GEMASTIK19{caesar_r0t_th1rt33n_klasik}
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```
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## Flag
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`GEMASTIK19{caesar_r0t_th1rt33n_klasik}`
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