TUM CTF 2016 – ndis (Crypto 300)

We have a HTTPS server and client talking to each other with you right in the middle! The client essentially executes curl –cacert server.crt https://nsa.gov with some magic to redirect the transmitted data to your socket, to which the server responds with a lovely German-language poem. NOTE: There is nothing else hosted on the server;… Continue reading »


Tokyo Westerns/MMA CTF 2016 – Backdoored Crypto System (Reverse+Crypto 400)

Get the flag. bcs.7z $ nc bcs.chal.ctf.westerns.tokyo 3971 Summary: recovering AES key from partial subkey leaks.


Google CTF – Wolf Spider (Crypto 125)

Continuing on from Eucalypt Forest – can you break Message Authentication in Wolf Spider wolf.py Summary: forging signatures by exploiting CBC padding oracle and hash length extenstion


Boston Key Party CTF 2016 – GCM (Crypto 9pts)

[8] : gsilvis counting magic – 9 – 4 solves : crypto: Here’s a verification/decryption server: gcm.ctf.bostonkey.party:32768 . Get the GCM MAC key (the thing the server prints out on startup). We’ve given you one valid ciphertext to get you started. It has iv: [102 97 110 116 97 115 116 105 99 32 105… Continue reading »


Dobbertin Challenge 2012

The Dobbertin Challenge is issued every two years since 2006, in honor and memory of Prof. Hans Dobbertin. http://cryptochallenge.nds.rub.de:50080/ A simple JSON Web Service is provided, which processes PIN codes of users. A user can send his encrypted PIN to the Web Service, which decrypts and stores the PIN. The Web Service allows to use… Continue reading »


Hack.lu 2012 CTF Challenge #12 (500)

The famous zombie researcher “Donn Beach” almost created an immunization against the dipsomanie virus. This severe disease leads to the inability to defend against Zombies, later causes a complete loss of memory and finally turns you into one of them. Inexplicably Donn forgot where he put the license key for his centrifuge. Provide him a… Continue reading »


PlaidCTF 2012 – Encryption Service [300] (Password Guessing)

We found the source code for this robot encryption service, except the key was redacted from it. The service is currently running at Summary: IV predict, byte-by-byte bruteforce


Hack.lu 2010 CTF Challenge #8 Writeup

Sad Little Pirate (150) Our sad little pirate haes lost his password. It is known that the pirate has just one hand left; his left hand. So the paessword input is quite limited. Also he can still remember that the plaintext started with “674e2” and his password with “wcwteseawx” Please help the sad pirate finding… Continue reading »