Challenge list
ProgrammingLevel 2★★☆☆☆Python Automation - Access Log Parsing
data.txt (about 1,300 lines, created at every start) is a web server access log. Extract only the requests from…
ProgrammingLevel 2★★☆☆☆Python Automation - Password Hash Cracking
Examine data.txt (a list of SHA-256 digests) and wordlist.txt (800 four-character lowercase alphanumeric tokens), both…
CryptographyLevel 2★★☆☆☆RC4 Stream Cipher Weakness
RC4 was once widely used but is now deprecated. This introductory task focuses on recognizing the provided data…
CryptographyLevel 2★★☆☆☆Vigenere Cipher Decryption
Decrypt a Vigenere cipher when the key length is known and retrieve the flag. Ciphertext:…
CryptographyLevel 2★★☆☆☆Finding Hash Collisions
MD5 collisions are practical. Hashes with broken collision resistance must not be used for security-sensitive…
CryptographyLevel 2★★☆☆☆Hash Length Extension Attack
Simple signatures such as hash(secret || message) can be vulnerable to length extension attacks with Merkle-Damgard…
CryptographyLevel 2★★☆☆☆Padding Oracle Basics
Padding oracle attacks use error differences as a plaintext recovery signal. This introductory task decodes leaked…
ProgrammingLevel 2★★☆☆☆Programming - Bash Job Log Analysis
/challenge/jobs.log is a nightly batch log that is regenerated with random data every time the container starts. Each…
ProgrammingLevel 2★★☆☆☆Programming - PIN Brute Force
/challenge/vault.json is a vault record that is regenerated with random data every time the container starts. It…
ProgrammingLevel 2★★☆☆☆Programming - Hash Verification and Decryption
Analyze the evidence file artifact-manifest.json, which is generated randomly at every start. Each artifact…
ProgrammingLevel 2★★☆☆☆Programming - Binary TLV Parsing
/challenge/capture.bin is a custom binary file that is regenerated with random data every time the container starts.…
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…