Cryptax
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Crypto: Dragon’s Crib Our team spent considerable time on this challenge, which only provided 50 points in the end. True, it was easier than I had expected, but still I think it deserved more points.
We are provided with an encryption algorithm, implemented in Python, and 5 ciphertexts:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 import binascii import random import sys SEED = random.
Forensics: Rexer This is what the challenge says:
1 2 3 4 5 6 7 The pattern is the key. \w*(3).+(T).*([s]).+(g).*([NT]r).*(u).+(L)\w+(Sm).*(N).*}$ asonV3l113UYnrvTfeJpsaeR}ZkJRvA{ThKgr730gnwWhYgVnNTSuhbpJ_BPn7Q8Q7mLnTrc_S3_p3zpFV8Fmm0hrUbvt_24upiqAt7ugXuhbpJ_BPn7Q8Q7mLq8qsSml4Sl4xmw1ON} \2OREO\9{\8\6\4\4\7\1_\3\5\6\4\4\7\1} The first pattern selects parts within the string (second line). Then, the third line re-assembles the selected groups to form the flag.
At first, I tried to use ChatGPT to help me out with the regexp. It didn’t work out well and I used Regex101.
This website is very convenient.
Hidden in Brucon “It appears a flag has hidden itself inside the brucon logo, can you retrieve it?” A file named brucon.jpg is provided.
The solution was very easy:
1 2 $ file brucon.jpg brucon.jpg: JPEG image data, JFIF standard 1.01, aspect ratio, density 1x1, segment length 16, comment: "TOREON{4lw4Ys_CHeck_MEt4Dat4}", progressive, precision 8, 842x595, components 3 Flag: TOREON{4lw4Ys_CHeck_MEt4Dat4}
Hidden inside the House 1 One day, I got an email from a friend containing a picture.