2025no writeups on CTFtime
Junior.Crypt.2025 CTF
28 challenges with 36 published solutions between them. CTFtime lists this event but has no writeups filed against it, so it is absent from the index CTFtime feeds. These were found in public repositories instead. Each link is pinned to the commit it was read from.
The event on CTFtimeUncategorised24
The upstream scoreboard did not say, so neither do we.
LCG Hack
3 official solutionsRecovery Password
3 official solutions100 percent Robust PRNG
2 official solutionsGoldenByte
2 official solutionsRobust PRNG in Python
2 official solutionsBroken ZKP
1 official solutionCompiled Python
1 official solutionCompiled Python Deception
1 official solutionDynamic Key
1 official solutionECDSA Nonce Reuse
1 official solutionError another error
1 official solutionGrey Box Hacking
1 official solutionHomomorphic Fraud
1 official solutionHomomorphic Weak
1 official solutionInteresting WAV
1 official solutionLiberty Bell
1 official solutionNotGeometry
1 official solutionPython PRNG Hack
1 official solutionRainbow in White
1 official solutionRobust PRNG
1 official solutionSuper Secret File
1 official solutionWhite Cat in a White Room
1 official solutionZKP 9+
1 official solutionZKP with Hint
1 official solution
Misc2
Everything that fits no other box: esolangs, puzzles, scripting exercises, and the jail escapes that have not yet earned their own category.
Solve it with:Brainfuck and esolang decoderCipher identifier and automatic decoderRegex tester with match offsets and capture groupsLearn: Recognising encodings
100% Robust PRNG
1 official solutionIntel vs Network Order
1 official solution
Steganography1
Find the payload hidden inside a carrier that looks ordinary. Bit planes, appended data, metadata, and audio spectrograms.
Solve it with:LSB steganography extractorPNG chunk analyzerAudio spectrogram and SSTV decoderZero-width character and text steganography decoderLearn: Steganography
Lonely Squirrel Blues
2 official solutions
Reverse engineering1
Work out what a compiled program does without its source, then work backwards from the check to the input that passes it.
Solve it with:Strings extractor for binaries and blobsWebAssembly disassemblerJava .class disassemblerPython .pyc bytecode disassemblerLearn: Binary exploitation
Puzzle
1 official solution