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BroncoCTF 'Spot the Difference' Challenge Solved Using Python difflib

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A BroncoCTF challenge presented participants with two nearly identical text files, file1.txt and file2.txt, and tasked them with finding hidden differences. The files contained 350 and 351 lines respectively, meaning a simple positional zip() comparison would silently desync after any insertion or deletion. Using Python's difflib.SequenceMatcher allowed for proper sequence alignment, surfacing 79 total differing positions across both files. Most differences turned out to be case-only flips serving as visual noise, while 29 meaningful substitutions spelled out the hidden flag. The challenge highlighted the importance of filtering out trivial transformations to isolate the real signal within a noisy diff.

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