BroncoCTF : Spot the difference Writeup

Short summary

A CTF writeup for the 'Spot the difference' challenge where two nearly identical files must be compared to extract a hidden flag. The author uses Python's difflib.SequenceMatcher instead of naive zip-based comparison to handle insertions and deletions correctly. After filtering out case-only noise from 79 differences, 29 meaningful character substitutions reveal the flag: bronco{y@yyy_Y0u_f0und_m3!!}.

• •Two files differ in 79 positions but most are case-only noise hiding the real signal
• •Python difflib.SequenceMatcher handles insertions/deletions better than naive zip comparison
• •Filtering case-only flips reveals 29 meaningful character substitutions forming the flag

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