stegoPromedium
Unsettled Huffman
volgactf
Task: ZIP archive with deflate-compressed PNG that is larger after compression; challenge hints at Huffman/deflate. Solution: parse raw deflate bitstream, extract block type (stored=1, fixed Huffman=0) from each of 435 blocks, decode bits as ASCII to recover the flag.
$ ls tags/ techniques/
deflate_block_type_steganographyzip_internal_structure_analysisraw_bitstream_parsingbait_decoy_identification
π
Permission denied (requires tier.pro)
Sign in to access full writeups
Sign in with GitHub to continue. No email required.
$sign in$ grep --similar
Similar writeups
- [reverse][Pro]Cursed Steganographyβ duckerz
- [forensics][Pro]Skeletonβ tjctf
- [forensics][Pro]π΄πingβ bluehensctf
- [reverse][Pro]Broken Treeβ grodno_new_year_2026
- [forensics][Pro]Name Callingβ bluehensctf