Challenge list
CryptographyLevel 2★★☆☆☆Rainbow Table Attack
Unsalted fast password hashes can often be reversed with precomputed lookup databases. Reverse the given MD5 hash. MD5…
CryptographyLevel 2★★☆☆☆One-Time Pad Key Reuse Attack
A one-time pad is safe only when the key is used once. Reusing the key lets known plaintext recover other plaintexts.…
CryptographyLevel 2★★☆☆☆Predictable Randomness
Pseudo-random output with a fixed seed is reproducible and must not be used for cryptographic secrets. Flag generation…
CryptographyLevel 2★★☆☆☆Breaking Small RSA Keys
Factor a tiny RSA modulus, recover the private exponent, and decrypt a list of ciphertext values. Public key and…
CryptographyLevel 2★★☆☆☆Cryptanalysis - Breaking the Affine Cipher
ciphertext.txt is an English report encrypted with the affine cipher E(x) = (a*x + b) mod 26. Letter case is preserved…
ProgrammingLevel 2★★☆☆☆Regular Expressions - The One-Time Golden Glyph
Extract every KINO-four-digits-four-uppercase glyph from data.txt, identify the one occurring once, and submit it to…
ProgrammingLevel 3★★★☆☆Python Automation - SQLite Database Analysis
Examine data.db (SQLite: users / orders / audit_log), created at every start. Aggregate orders per user_id with…
ProgrammingLevel 3★★★☆☆Python Automation - Custom Cipher Decryption
cipher.txt holds the flag encrypted with a custom cipher (hex). Encryption applies per byte: add (key), xor…
ProgrammingLevel 3★★★☆☆Python Automation - Encrypted ZIP Password Cracking
A new /challenge/secret.zip is created at every start. It contains flag.txt and readme.txt, encrypted with ZipCrypto.…
ProgrammingLevel 3★★★☆☆Algorithms - BFS Shortest Path Through a Maze
Use BFS to find the shortest path from S to E in data.txt, then submit the UDLR move sequence to challenge.py. A…
ProgrammingLevel 3★★★☆☆Programming - SQLite Evidence Database
evidence.db is a SQLite database built from random data at every start (in /challenge, with the tables users /…
ProgrammingLevel 3★★★☆☆Programming - Web Scraping Graph Traversal
site.json is a crawl result built from random data at every start (in /challenge). It holds the start and target URLs…
ProgrammingLevel 3★★★☆☆Programming - ZIP Password Recovery
secret.zip is a ZIP encrypted with ZipCrypto (the traditional PKWARE cipher), created at every start (in /challenge,…
ProgrammingLevel 3★★★☆☆Programming - Packet Log Analysis
capture.txt is a packet log created at every start (in /challenge). Each line is one flow of the form flow=<name>…
ProgrammingLevel 3★★★☆☆Programming - Multithreaded Result Reassembly
Analyze the parallel-job result log worker-results.jsonl, which is generated randomly at every start. Each slot was…
ProgrammingLevel 3★★★☆☆Programming - Memory Dump Analysis
Analyze the synthetic memory image memory.img, which is generated randomly at every start. In the heap table at the…
ProgrammingLevel 3★★★☆☆Programming - Known-Plaintext Attack
Analyze the evidence files ciphertext.b64 and known.txt, which are generated randomly at every start. ciphertext.b64…
ProgrammingLevel 3★★★☆☆Programming - Custom Protocol Parsing
protocol.bin is a binary capture created at every start (in /challenge): several length-prefixed frames that begin…
ProgrammingLevel 3★★★☆☆Programming - Image Steganography
image.pgm is a text-format (P2) PGM image created at every start (in /challenge). Collect the least significant bit…
CryptographyLevel 3★★★☆☆Cryptanalysis - RSA Common Modulus Attack
Two systems reused the same RSA modulus n and only changed the public exponent. The ciphertexts c1 and c2 of the same…
CryptographyLevel 3★★★☆☆Cryptanalysis - Diffie-Hellman with a Small Prime
An old IoT device performed Diffie-Hellman key exchange with a prime p of only 36 bits. handshake.txt contains p, g, A…
ProgrammingLevel 4★★★★☆Advanced Python - Custom VM Bytecode Execution
program.kvm is bytecode for a custom four-register VM. Implement an interpreter in Python from the instruction…
ProgrammingLevel 4★★★★☆Binary Repair - Firmware Header and CRC32
Repair firmware.bin by writing KINO at bytes 0-3 and the little-endian CRC32 of bytes 12+ at bytes 8-11. Submit the…
ProgrammingLevel 4★★★★☆Programming - C2 Traffic Analysis
Analyze the synthetic log beacon.log, which is generated randomly at every start (no network connection is needed).…