0ops Cipher 4, hope you enjoy it:) zer0C4.zip nc 202.120.7.220 1234 Summary: related-key attack on weakened variant of RC4
Tag: 0ctf
Apr 02
0CTF 2018 Quals – zer0SPN (Crypto 550)
0ops SPN, hope you enjoy it:) zer0SPN.zip Summary: linear cryptanalysis on toy block cipher
Apr 02
0CTF 2018 Quals – zer0TC (Crypto 916)
0ops Toy Cipher, hope you enjoy it:) zer0TC.zip Summary: meet-in-the-middle and key-schedule constraints
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 …
Mar 20
0CTF 2017 Quals – OneTimePad 1 and 2
I swear that the safest cryptosystem is used to encrypt the secret! oneTimePad.zip Well, maybe the previous one is too simple. So I designed the ultimate one to protect the top secret! oneTimePad2.zip Summary: breaking a linear and an LCG-style exponential PRNGs.
Mar 14
0CTF 2016 Quals – Equation (Crypto 2 pts)
Here is a RSA private key with its upper part masked. Can your recover the private key and decrypt the file? equation.zip Summary: recovering RSA key from part of the private key.
Mar 13
0CTF 2016 Quals – RSA? (Crypto 2 pts)
It seems easy, right? rsa.zip Tip: openssl rsautl -encrypt -in FLAG -inkey public.pem -pubin -out flag.enc Summary: factoring 300-bit modulus into 3 primes, extracting cube roots.