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Home FinalTrace 2025 Lost Core Pulse
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Lost Core Pulse

Lost Core Pulse

  • Category: Crypto
  • Author: Varsaa H

Challenge Description

The Eon city’s memory pulse went missing in a turbulent transmission. What remains in cipher.txt is cloaked with layers recognizable only to cryptographers—and those attentive to the patterns of Eon’s lost pulse.

Hint: Sometimes, signals are wrapped not once but twice.


Solution

Initial Analysis

  • Downloaded and inspected the file cipher.txt.
  • The content was a long string of what looked like hexadecimal characters.

Tools Used

  • Python (hex and base64 decoding)
  • CyberChef (for alternate handy decoding)
  • Any text editor

Step-by-Step Solution

Step 1: Hex Decode the cipher.txt

with open(‘cipher.txt’) as f: data = bytes.fromhex(f.read()) print(data)

This produced a result that looked like base64: b’Q1lTezNiYjEyZGF9b3N0cHVsc2VFOTFiZTJkZTFkZjQ=’

Step 2: Base64 Decode the Result

import base64 flag = base64.b64decode(data).decode() print(flag)

text Output: CYS{3bb12d_lostpulse_91be2d}

This is the flag, revealed from the two encoding layers.

Flag

CYS{3bb12d_lostpulse_91be2d}

Flag

CYS{3bb12d_lostpulse_91be2d}
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