0ops Toy Cipher, hope you enjoy it:) zer0TC.zip Summary: meet-in-the-middle and key-schedule constraints
Tag: aes
Mar 20
0CTF 2017 Quals – Zer0llvm
Talent Yang loves to customize his own obfuscator. Unfortunately, he lost his seed when he was watching Arsenal’s UEFA game. What a sad day! His team and his seed were lost together. To save him, could you help him to get back his seed? We can not save the game, but we may be able …
Oct 02
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; …
Sep 05
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.
May 01
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
Mar 07
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 …
Nov 13
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 …
Nov 04
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 …
May 01
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 23.21.15.166:4433 Summary: IV predict, byte-by-byte bruteforce
Oct 30
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 …