Google CTF – Wolf Spider (Crypto 125)

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


PlaidCTF 2016 – sexec (Crypto 300)

If you need to securely grant execution privileges, what better way to do it than sexec? This is running on sexec.tar.gz Summary: attacking a small instance of Ring-LWE based cryptosystem with Babai’s Nearest Vector algorithm.


Boston Key Party CTF 2016 – Feistel (Crypto 5pts)

feistel – 5 – 15 solves : crypto: I just made a brand new cipher! Can you recover the key? feistel.go Summary: slide with a twist attack


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

[8] : gsilvis counting magic – 9 – 4 solves : crypto: Here’s a verification/decryption server: . 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 »


Boston Key Party CTF 2016 – HMAC-CRC (Crypto 5pts)

[3] : hmac_crc – 5 – 36 solves : crypto: We’re trying a new mac here at BKP—HMAC-CRC. The hmac (with our key) of “zupe zecret” is ‘0xa57d43a032feb286’. What’s the hmac of “BKPCTF”? Summary: breaking HMAC-CRC (again)


DEFCON CTF Survival Guide (2014)

vos and snk from MSLC share their basic view of Attack-Defence CTFs and tell random stories in their two-hour talk at Chaos Constructions 2014.   With English subtitles


CONFidence CTF 2015 – RSA2 (Crypto 500)

Find the flag data Summary: cube attack + recover python’s MersenneTwister state + leak 320/520 LSBs of one of the primes


ASIS CTF Quals 2015 – Cross Check (Crypto 350)

The flag is encrypted by this code, can you decrypt it? crosscheck.tar.xz Summary: breaking RSA modulos with related primes.


VolgaCTF Quals 2015 – CPKC (Crypto 400) writeup

cpkc A home-brewed cryptosystem, should be easy to break. Its keyspace seems to be rather large though… challenge.tar Summary: LLL-based attack on NTRUEncrypt-like cryptosystem.


PlaidCTF 2014 wheeeee writeup

Although it seems like The Plague’s messaging service is secure, there are bound to be bugs in any 20th century crypto system. We’ve recovered a version of the block cipher The Plague implemented. Use their online encryptor tool, at, to break the cipher and figure out Plague’s secret plans. NOTE: When the service sends… Continue reading »


PlaidCTF 2014 parlor writeup

The Plague is running a betting service to build up funds for his massive empire. Can you figure out a way to beat the house? The service is running at


PlaidCTF 2014 __nightmares__ writeup

The Plague is building an army of evil hackers, and they are starting off by teaching them python with this simple service. Maybe if you could get full access to this system, at, you would be able to find out more about The Plague’s evil plans. Code: (can be run locally with $ socat… Continue reading »


PlaidCTF 2014 RSA writeup

Our archaeologists recovered a dusty and corrupted old hard drive used by The Plague in his trips into the past. It contains a private key, but this has long since been lost to bitrot. Can you recover the full key from the little information we have recovered?


Boston Key Party CTF – Differential Power (Crypto 400)

we hooked up a power meter to this encryption box. we don’t know the key. that’s what we want to know. you can encrypt any string of 8 characters on the service encrypt.asm chall source (released after ctf)


Codegate 2014 Quals – Minibomb (pwn 400)

□ description ========================================== ssh guest@ / ExtremelyDangerousGuest ssh guest@ / ExtremelyDangerousGuest ========================================== □ number of solvers : 15 □ breakthrough by 1 : More Smoked Leet Chicken (02/23 02:38) 2 : Hexcellents (02/23 02:42) 3 : ppp (02/23 03:16) Binary

Older posts «

» Newer posts