picoCTF Write-up 01 / 06 · Reversing / Linux / Encoding · 2025
Text Transformations.
Multi-stage flag recovery challenge requiring sequential reversal of encoding transformations. Each step reveals the next transformation to undo.
Linux CLIbase64revtrROT13
Method
Solution path.
01
Base64 decode:
base64 -d → reversed string02
Text reversal:
rev → corrected character order03
Character substitution:
tr '-' '_' → restore underscores04
Delimiter swap:
tr '()' '{}' → fix curly braces05
ROT13 cipher:
tr 'a-zA-Z' 'n-za-mN-ZA-M' → final flagFlag (spoiler)
picoCTF{Revers1ng_t3xt_Tr4nsf0rm@t10ns_dcc1896c}