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picoCTF

01 January 1337

Babygame01

Get the flag and reach the exit. Welcome to BabyGame! Navigate around the map and see what you can find!...

pwn, out-of-bounds

picoCTF

01 January 1337

Buffer Overflow 2

Control the return address and arguments This time you'll need to control the arguments to the function you return to!...

pwn, buffer-overflow, ret-to-win, args-on-stack, gets

picoCTF

01 January 1337

Buffer Overflow 3

Do you think you can bypass the protection and get the flag? It looks like Dr. Oswal added a stack...

pwn, buffer-overflow, stack-canary, ret-to-win, byte-by-byte

picoCTF

01 January 1337

Flag Leak

Story telling class 1/2 I'm just copying and pasting with this [program](https://github.com/Nightxade/ctf-writeups/tree/master/assets/CTFs/picoCTF/flag-leak-vuln). What can go wrong? You can view [source](https://github.com/Nightxade/ctf-writeups/tree/master/assets/CTFs/picoCTF/flag-leak-vuln.c)...

pwn, format-strings, %p

picoCTF

01 January 1337

Rps

Here's a program that plays rock, paper, scissors against you. I hear something good happens if you win 5 times...

pwn, strstr

picoCTF

01 January 1337

X Sixty What

Overflow x64 code Most problems before this are 32-bit x86. Now we'll consider 64-bit x86 which is a little different!...

pwn, x64, buffer-overflow

picoCTF

01 January 1337

Aes Abc

AES-ECB is bad, so I rolled my own cipher block chaining mechanism - Addition Block Chaining! You can find the...

crypto, aes

picoCTF

01 January 1337

B00tl3grsa2

In RSA d is a lot bigger than e, why don't we use d to encrypt instead of e? Connect...

crypto, rsa

picoCTF

01 January 1337

B00tl3grsa3

Why use p and q when I can use more? Connect with `nc jupiter.challenges.picoctf.org 51575`. --- Connect to the service....

crypto, rsa, multi-prime

picoCTF

01 January 1337

College Rowing Team

I just joined my college's rowing team! To make a good first impression, I started sending my teammates positive automated...

crypto, rsa, unpadded

picoCTF

01 January 1337

Compress And Attack

Your goal is to find the flag. [compress_and_attack.py](https://github.com/Nightxade/ctf-writeups/tree/master/assets/CTFs/picoCTF/compress_and_attack.py) `nc mercury.picoctf.net [port #]` --- We’re given a file, `compress_and_attack.py` and a...

crypto, zlib, Salsa20, brute-force

picoCTF

01 January 1337

John Pollard

Sometimes RSA [certificates](https://github.com/Nightxade/ctf-writeups/tree/master/assets/CTFs/picoCTF/john-pollard-cert) are breakable --- We're given an RSA certificate. After a bit of research, I figured out the...

crypto, rsa, certificate

picoCTF

01 January 1337

Mini Rsa (both)

Let's decrypt this: [ciphertext](https://github.com/Nightxade/ctf-writeups/tree/master/assets/CTFs/picoCTF/mini-rsa-ciphertext)? Something seems a bit small. --- *Note that the methods for this challenge work for both...

crypto, rsa, brute-force, small-e

picoCTF

01 January 1337

New Vignere

Another slight twist on a classic, see if you can recover the flag. (Wrap with picoCTF{}) `ioffdcjbfjmcifelcaloifgcjecgpgiebpfeiafhgajafkmlfcbpfbioflgcmacg` [new_vignere.py](https://github.com/Nightxade/ctf-writeups/tree/master/assets/CTFs/picoCTF/new_vignere.py) --- We’re...

crypto, vigenere, bits

picoCTF

01 January 1337

Nsa Backdoor

I heard someone has been sneakily installing backdoors in open-source implementations of Diffie-Hellman... I wonder who it could be... ;)...

crypto, diffie-hellman, rsa, smooth-primes, pollard-attack

picoCTF

01 January 1337

Rsa Pop Quiz

Class, take your seats! It's PRIME-time for a quiz... `nc jupiter.challenges.picoctf.org 18821` --- Connect to the service. The first problem...

crypto, rsa

picoCTF

01 January 1337

Scrambled Rsa

Hmmm I wonder if you have learned your lesson... Let's see if you understand RSA and how the encryption works....

crypto, rsa, brute-force, byte-by-byte

picoCTF

01 January 1337

Sra

I just recently learnt about the SRA public key cryptosystem... or wait, was it supposed to be RSA? Hmmm, I...

crypto, rsa, factorization, brute-force

picoCTF

01 January 1337

Sum O Primes

We have so much faith in RSA we give you not just the product of the primes, but their sum...

crypto, rsa

picoCTF

01 January 1337

Very Smooth

Forget safe primes... Here, we like to live life dangerously... >:) - [gen.py](https://github.com/Nightxade/ctf-writeups/tree/master/assets/CTFs/picoCTF/very-smooth-gen.py) - [output.txt](https://github.com/Nightxade/ctf-writeups/tree/master/assets/CTFs/picoCTF/very-smooth-output.txt) --- We’re given two files,...

crypto, rsa, smooth-primes, pollard-attack

picoCTF

01 January 1337

Waves Over Lambda

We made a lot of substitutions to encrypt this. Can you decrypt it? Connect with `nc jupiter.challenges.picoctf.org 13758`. --- Connecting...

crypto, monoalphabetic-substitution

picoCTF

01 January 1337

Operation Oni

Download this disk image, find the key and log into the remote machine. Note: if you are using the webshell,...

forensics, disk, permissions

picoCTF

01 January 1337

Operation Orchid

Download this disk image and find the flag. Note: if you are using the webshell, download and extract the disk...

forensics, disk, openssl

picoCTF

01 January 1337

Sidechannel

There's something fishy about this PIN-code checker, can you figure out the PIN and get the flag? Download the PIN...

forensics, side-channel, timing

picoCTF

01 January 1337

Whitepages

I stopped using YellowPages and moved onto WhitePages... but the page they gave me is all blank! [whitepages.txt](https://github.com/Nightxade/ctf-writeups/tree/master/assets/CTFs/picoCTF/whitepages.txt) --- ```xxd...

forensics, unicode, binary

picoCTF

01 January 1337

picoCTF

[picoCTF](https://picoctf.org/) This was the CTF I first started off with! In early July 2023 I was introduced to picoCTF and...

picoCTF

picoCTF

01 January 1337

Otp Implementation

Yay reversing! Relevant files: [otp](https://github.com/Nightxade/ctf-writeups/tree/master/assets/CTFs/picoCTF/otp) [flag.txt](https://github.com/Nightxade/ctf-writeups/tree/master/assets/CTFs/picoCTF/otp-flag.txt) --- We're given an ELF binary `otp` and a `flag.txt` that contains the encrypted...

rev, otp, byte-by-byte

picoCTF

01 January 1337

Reverse Cipher

We have recovered a [binary](https://github.com/Nightxade/ctf-writeups/tree/master/assets/CTFs/picoCTF/rev-cipher-rev) and a [text file](https://github.com/Nightxade/ctf-writeups/tree/master/assets/CTFs/picoCTF/rev-cipher-rev_this). Can you reverse the flag. --- We're given an ELF binary...

rev

picoCTF

01 January 1337

Irish Name Repo 1

There is a website running at https://jupiter.challenges.picoctf.org/problem/50009/ ([link](https://jupiter.challenges.picoctf.org/problem/50009/)) or http://jupiter.challenges.picoctf.org:50009. Do you think you can log us in? Try to...

web, sql-injection

picoCTF

01 January 1337

Irish Name Repo 2

There is a website running at https://jupiter.challenges.picoctf.org/problem/53751/ ([link](https://jupiter.challenges.picoctf.org/problem/53751/)). Someone has bypassed the login before, and now it's being strengthened. Try...

web, sql-injection

picoCTF

01 January 1337

Irish Name Repo 3

There is a secure website running at https://jupiter.challenges.picoctf.org/problem/40742/ ([link](https://jupiter.challenges.picoctf.org/problem/40742/)) or http://jupiter.challenges.picoctf.org:40742. Try to see if you can login as admin!...

web, sql-injection, curl

picoCTF

01 January 1337

Roboto Sans

The flag is somewhere on this web application not necessarily on the website. Find it. Check [this](http://saturn.picoctf.net:63195/) out. --- After...

web, robots.txt

picoCTF

01 January 1337

Secrets

We have several pages hidden. Can you find the one with the flag? The website is running [here](http://saturn.picoctf.net:62050/). --- `curl...

web, curl

1337UP-LIVE-CTF-2023

27 November 2023

Keyless

My friend made a new encryption algorithm. Apparently it's so advanced, you don't even need a key! [flag.txt.enc](https://github.com/Nightxade/ctf-writeups/tree/master/assets/CTFs/1337UP-LIVE-CTF-2023/flag.txt.enc) [encrypt.py](https://github.com/Nightxade/ctf-writeups/assets/CTFs/1337UP-LIVE-CTF-2023/encrypt.py) ---...

crypto, rev

1337UP-LIVE-CTF-2023

27 November 2023

Not So Smooth

Can you find a and b? [notsosmooth.py](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/1337UP-LIVE-CTF-2023/notsosmooth.py) --- We're given the following: ```py from Crypto.Util.number import long_to_bytes from Crypto.Util.strxor import...

crypto, xor, modular-arithmetic

1337UP-LIVE-CTF-2023

27 November 2023

Really Secure Apparently

Apparently this encryption is "really secure" and I don't need to worry about sharing the ciphertext, or even these values.....

crypto, rsa, wiener

1337UP-LIVE-CTF-2023

27 November 2023

1337UP LIVE CTF 2023

[](https://ctftime.org/event/2134) Placement: #133/691 --- ## Thoughts: I had a lot of fun with this CTF! I didn't really solve anything...

1337UP-LIVE-CTF-2023

1337UP-LIVE-CTF-2023

27 November 2023

Flag Checker

Can you beat this FlagChecker? [flagchecker](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/1337UP-LIVE-CTF-2023/flagchecker) [source.rs](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/1337UP-LIVE-CTF-2023/source.rs) --- ### *Warning: if you came here for an elegant solution, this is...

rev, rust, brute-force

1337UP-LIVE-CTF-2023

27 November 2023

Obfuscation

I think I made my code harder to read. Can you let me know if that's true? [obfuscation.zip](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/1337UP-LIVE-CTF-2023/obfuscation.zip) --- This...

rev, obfuscation, xor

1337UP-LIVE-CTF-2023

27 November 2023

Encoding

I have no idea what this message means, can you help me decipher it? 👨‍💻 [enc.txt](https://github.com/Nightxade/ctf-writeups/tree/master/assets/CTFs/1337UP-LIVE-CTF-2023/enc.txt) --- We're given a...

warmup, encoding, base32, base64, hex, morse

1337UP-LIVE-CTF-2023

27 November 2023

Flag Extraction

They told me I just need to extract flag but I don't know what that means?! [flag.rar](https://github.com/Nightxade/ctf-writeups/tree/master/assets/CTFs/1337UP-LIVE-CTF-2023/flag.rar) --- After extracting...

warmup, rar, zip, binwalk

1337UP-LIVE-CTF-2023

27 November 2023

Over The Wire 1

I'm not sure how secure this protocol is but as long as we update the password, I'm sure everything will...

warmup, network, wireshark, ftp

1337UP-LIVE-CTF-2023

27 November 2023

Over The Wire 2

Learning the lessons from the previous failed secure file transfer attempts, CryptoCat and 0xM4hm0ud found a new [definitely secure] way...

warmup, network, wireshark, stego, lsb

Newport-Blake-CTF-2023

04 December 2023

Gym

Bro kroot. Ignore the time/memory/input/output section of the pdf. `nc chal.nbctf.com 30270` [gym.pdf](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/Newport-Blake-CTF-2023/algo/gym.pdf) --- Okay, so we're given a sequence...

algo, greedy

Newport-Blake-CTF-2023

04 December 2023

32+32=64

64 is too much, but 32 isn't. 32+32=64? [32_1.txt](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/Newport-Blake-CTF-2023/crypto/32_1.txt) [32_2.txt](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/Newport-Blake-CTF-2023/crypto/32_2.txt) --- We're given two base64 strings. Each of them, when...

crypto, base64

Newport-Blake-CTF-2023

04 December 2023

Caesar Salads

Every CTF needs an introductory crypto. I found a roman emperor that made this super cool cipher. Can you decrypt...

crypto, caesar

Newport-Blake-CTF-2023

04 December 2023

Rivest Shamir Forgot Adleman

Exponents took too long. I decided to use an alternative. It won't about the same right? https://en.wikipedia.org/wiki/RSA(cryptosystem) [output.txt](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/Newport-Blake-CTF-2023/crypto/rsa-output.txt) [chall.py](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/Newport-Blake-CTF-2023/crypto/rsa-chall.py) ---...

crypto, rsa, broken-rsa

Newport-Blake-CTF-2023

04 December 2023

Sbg Abw's Insanity

"Skill Issue" - AnonymousBlueWhale [output.txt](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/Newport-Blake-CTF-2023/crypto/sbg-abw-output.txt) [chall.py](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/Newport-Blake-CTF-2023/crypto/sbg-abw-chall.py) --- We're given `chall.py` and `output.txt`. Here's `chall.py`: ```py from Crypto.Util.number import getPrime, bytes_to_long,...

crypto, rsa

Newport-Blake-CTF-2023

04 December 2023

Newport Blake CTF 2023

[](https://ctftime.org/event/2072) Overall Placement: #29/451 High School Placement: #8/39 --- ## Thoughts: First high school CTF! Overall, I think I did...

Newport-Blake-CTF-2023

Newport-Blake-CTF-2023

04 December 2023

Do You Hear That

I'm not sure why, but when I look at this image I can hear some sort of faint sound. Do...

misc, forensics, audio-forensics

Newport-Blake-CTF-2023

04 December 2023

Not Accepted

I can't seem to pass this problem... can you help me? [https://codeforces.com/contestInvitation/9cf6e56adf19ecb8e5dd7af8a9c5bf5610c8e46e](https://codeforces.com/contestInvitation/9cf6e56adf19ecb8e5dd7af8a9c5bf5610c8e46e) --- We're given an odd Codeforces problem: Simply...

misc, codeforces

Newport-Blake-CTF-2023

04 December 2023

Babbling About

They say a monkey with a typewriter will eventually type out a masterpiece. But what about a flag? Enclose the...

osint, babel

Newport-Blake-CTF-2023

04 December 2023

Linkedout 1

I’ve just finished setting up Newport blakes LinkedIn! I hope I didn't give away too much personal information in my...

osint, hex

Newport-Blake-CTF-2023

04 December 2023

Linkedout 3

Lets see your linkedin experience. There's another flag hidden somewhere, lets see if you can find it. --- Take a...

osint, hex

Newport-Blake-CTF-2023

04 December 2023

Persona

I have this username, can you help me uncover who it really is? They go by the name in2win9945 online....

osint, wayback-machine

Newport-Blake-CTF-2023

04 December 2023

Webcam

인터넷에서 웹캠을 잃어버렸습니다. 정확히 어디에 있는지 알려주실 수 있나요? Flag is the coordinates of the location truncated to three digits,...

osint, google-maps

Newport-Blake-CTF-2023

04 December 2023

Crisscross

X [output.txt](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/Newport-Blake-CTF-2023/rev/output.txt) [main.py](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/Newport-Blake-CTF-2023/rev/main.py) --- We're given `main.py` and `output.txt`. Here's `main.py`: ```py import random key1 = random.choices(range(256), k=20) key2 =...

rev, bits

Newport-Blake-CTF-2023

04 December 2023

Itchy Scratchy

Yeah sorry, I couldn't resist. Use Turbowarp if you want. [itchyscratchy.sb3](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/Newport-Blake-CTF-2023/rev/itchyscratchy.sb3) --- Head over to Turbowarp and load the Scratch...

rev, Scratch, brute-force

Newport-Blake-CTF-2023

04 December 2023

Shifty Sands

Can you escape the sand-filled maze before it's too late? `nc chal.nbctf.com 30401` [sands](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/Newport-Blake-CTF-2023/rev/sands) --- We're given an ELF binary,...

rev, maze

Newport-Blake-CTF-2023

04 December 2023

Inspector Gadget

While snooping around this website, inspector gadet lost parts of his flag. Can you help him find it? [inspector-gadget.chal.nbctf.com](inspector-gadget.chal.nbctf.com) ---...

web, inspect

Newport-Blake-CTF-2023

04 December 2023

Secret Tunnel

Can you find the flag on the other end of my secret tunnel? [secret-tunnel.chal.nbctf.com](secret-tunnel.chal.nbctf.com) [secret_tunnel.zip](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/Newport-Blake-CTF-2023/web/secret-tunnel.zip) --- We're given a website...

web, localhost, url-encoding

Newport-Blake-CTF-2023

04 December 2023

Walter's Crystal Shop

My buddy Walter is selling some crystals, check out his shop! [walters-crystal-shop.chal.nbctf.com](walters-crystal-shop.chal.nbctf.com) [walters_crystal_shop.zip](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/Newport-Blake-CTF-2023/web/walters_crystal_shop.zip) --- The source includes an `app.js` file....

web, SQLi, sql-union

Hackappatoi-CTF-2023

10 December 2023

Hackappatoi CTF 2023

[](https://ctftime.org/event/2163) #116/443 --- ## Thoughts: Didn't have much time to play this CTF, but I did still manage to solve...

Hackappatoi-CTF-2023

Hackappatoi-CTF-2023

10 December 2023

Escape From Italy

Italy is maybe the most touristic country around the world, amazing food, spectacular monuments, and faboulus environments But in the...

misc, py-jail, ruby-jail

Hackappatoi-CTF-2023

10 December 2023

Italian Mail

Enzo Tommasi was a YouTube "superstar" in Italy. He went viral with this video initially and then with many others....

osint, google-maps

Hackappatoi-CTF-2023

10 December 2023

The First Horseman

I don’t think you’re welcome inside this castle… SHISH! [thefirsthorseman](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/Hackappatoi-CTF-2023/thefirsthorseman38.pyc) --- We're provided a `.pyc` file. For those who are...

rev, pyc, rot13

Hackappatoi-CTF-2023

10 December 2023

The Four Horseman

The Cavaliere is returned. He is awake and he’s ready to unleash the apocalypse. Are you the chosen one? Solving...

rev, rot13

Hackappatoi-CTF-2023

10 December 2023

Lemons

Perhaps not everyone knows that Italy produces top-quality lemons. No wonder that forgetting them at the counter is a very...

web, robots.txt

ping-CTF-2023

11 December 2023

Hard Work

You've received a cryptic message from your boss at the company. Apparently, your aggressive demeanor has raised concerns, and your...

crypto, encoding

ping-CTF-2023

11 December 2023

Lame Lame Loser

In this challenge, your school teacher dismissed your abilities by calling you a lame loser. Now, you have the chance...

crypto, lll

ping-CTF-2023

11 December 2023

Old Friend From The Past

You've stumbled upon an encrypted message from the past, a mysterious code left behind by a figure from history. Your...

crypto, caesar

ping-CTF-2023

11 December 2023

Private Conversation

Welcome to the "private-conversation" challenge, where you find yourself in the role of a cryptanalyst facing an intriguing encrypted message....

crypto, encoding, obfuscation

ping-CTF-2023

11 December 2023

ping CTF 2023

[](https://ctftime.org/event/1987) Overall Placement: #63/517 --- ## Thoughts: This was a fun CTF! I was admittedly a little frustrated with my...

ping-CTF-2023

ping-CTF-2023

11 December 2023

Inside Bear

This is the hardest reversing challenge I've ever met!!! Can you please help me? It even has source code attached...

misc, binwalk, audio-forensics, spectrogram

ping-CTF-2023

11 December 2023

Imag Ine An Elf

This is no ordinary reversing challenge! As the Christmas season is coming, we thought that a real elf would be...

rev, lsb

ping-CTF-2023

11 December 2023

Noodle Nightmare

In the last programming session, Bajtek unleashed a coding catastrophe – his spaghetti code was so messy that even the...

rev, obfuscation

ping-CTF-2023

11 December 2023

Ziggarettes

Don't smoke zigarettes, kids! [e0d8bf8fdefc32df23a1c96f047c50fc.zip](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/ping-CTF-2023/e0d8bf8fdefc32df23a1c96f047c50fc.zip) --- We're given an ELF binary. I decompiled with [Dogbolt](https://dogbolt.org/) and examined the Ghidra code....

rev

ping-CTF-2023

11 December 2023

Path Traversal 101

Can you pass the path traversal exam? 👀 There might be some requirements tho for your *specie*... [https://path-traversal-101.knping.pl](https://path-traversal-101.knping.pl) [ec96a2a4ee45dd97dfa37319f21468a3.zip](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/ping-CTF-2023/ec96a2a4ee45dd97dfa37319f21468a3.zip) ---...

web, robots.txt, path

ping-CTF-2023

11 December 2023

Youtube Trailer

Watch the [PING CTF 2023 official trailer](https://www.youtube.com/watch?v=siZPvEGrtNY) and find the flag! --- Nothing on the video seemed to indicate a...

web, curl

Cyber-Cooperative-CTF-2023

19 December 2023

Slots

I heard about this [scam that let people rob some slot machines](https://www.wired.com/2017/02/russians-engineer-brilliant-slot-machine-cheat-casinos-no-fix/). Can you do it with this slot machine?...

crypto, randcrack

Cyber-Cooperative-CTF-2023

19 December 2023

Babyhide

This little baby is figuring out how to computer! It looks like the baby hid some of my files though....

forensics, binwalk

Cyber-Cooperative-CTF-2023

19 December 2023

Funding Secured

Someone in our company leaked some very sensitive information. We absolutely cannot let this stand. Thankfully our monitoring software intercepted...

forenics, lsb, binwalk

Cyber-Cooperative-CTF-2023

19 December 2023

Lost At Sea

I dropped my flag in the sea. Help me find it among the sharks! [lost-at-sea.pcapng](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/Cyber-Cooperative-CTF-2023/forensics/lost-at-sea.pcapng) --- We're given a very...

forensics, wireshark

Cyber-Cooperative-CTF-2023

19 December 2023

Cyber Cooperative CTF 2023

[](https://ctftime.org/event/2206) #121/432 --- ## Thoughts: I didn't perform too well on this CTF, but was still fun! I think I...

Cyber-Cooperative-CTF-2023

Cyber-Cooperative-CTF-2023

19 December 2023

Crashme

Can you make this program crash? `nc 0.cloud.chals.io 17289` [crashme](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/Cyber-Cooperative-CTF-2023/pwn/crashme) [crashme.c](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/Cyber-Cooperative-CTF-2023/pwn/crashme.c) --- We're given an ELF binary, a C source...

pwn, buffer-overflow, segfault

Cyber-Cooperative-CTF-2023

19 December 2023

Medbof

a little harder this time `nc 0.cloud.chals.io 27380` [medbof](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/Cyber-Cooperative-CTF-2023/pwn/medbof) --- We're given an ELF binary, `medbof`. I decompiled with [Dogbolt](https://dogbolt.org/)....

pwn, buffer-overflow, ret2win

Cyber-Cooperative-CTF-2023

19 December 2023

Bunker

You reach a large metal door. It's protected by large yellow bars. There appears to be an panel with a...

rev, jar

Cyber-Cooperative-CTF-2023

19 December 2023

Dis

Our field agents extracted the disassembly for a function that we think generates a secret flag. But it doesn't look...

rev, bytecode

Cyber-Cooperative-CTF-2023

19 December 2023

Easycrack

I need to make a key for this crackme for my homework. I just want to play video games, can...

rev

Iris-CTF-2024

07 January 2024

Baby Charge

For your first assignment, break ChaCha20! `nc babycha.chal.irisc.tf 10100` [babycha.tar.gz](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/Iris-CTF-2024/babycha.tar.gz) --- We're given an encryption oracle with two options --...

crypto, chacha20, oracle

Iris-CTF-2024

07 January 2024

Integral Communication

I've found this secret communication system running on a server. Unfortunately it uses AES so there's not much I can...

crypto, aes, aes-cbc, oracle, json

Iris-CTF-2024

07 January 2024

Iris CTF 2024

[](https://ctftime.org/event/2085) Placement: #88/1207 --- ## Thoughts: Turns out I'm a speed demon in the first few hours of the CTF,...

Iris-CTF-2024

Iris-CTF-2024

07 January 2024

Name That Song 3

No more modarchive. Find the original title of this song which has been redacted from this file. Format: irisctf{never_gonna_give_you_up} Song...

misc, reverse-audio-search

Iris-CTF-2024

07 January 2024

Sir Scope

This circuit used to write out the flag using an array of 8 LEDs, but the LEDs are all burnt...

misc, brute-force

Iris-CTF-2024

07 January 2024

Wheres Skat

While traveling over the holidays, I was doing some casual wardriving (as I often do). Can you use my capture...

network, osint, wifi

Iris-CTF-2024

07 January 2024

Away On Vacation

Iris and her assistant are away on vacation. She left an audio message explaining how to get in touch with...

osint, instagram

Iris-CTF-2024

07 January 2024

Czech Where

Iris visited this cool shop a while back, but forgot where it was! What street is it on? [czech-where.tar.gz](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/Iris-CTF-2024/czech-where.tar.gz) ---...

osint, reverse-image-search

Iris-CTF-2024

07 January 2024

Personal Breach

Security questions can be solved by reconnaissance. The weakest link in security could be the people around you. [https://personal-breach-web.chal.irisc.tf/](https://personal-breach-web.chal.irisc.tf/) ---...

osint, instgram, linkedin, facebook

Iris-CTF-2024

07 January 2024

Insanity Check

I've tried the brand new michael-ld linker on my hello world program. I'm pretty sure it's super safe now. `nc...

pwn, buffer-overflow, ret2win

Iris-CTF-2024

07 January 2024

Rune Whats That

Rune? Like the ancient alphabet? [whats-a-rune.tar.gz](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/Iris-CTF-2024/whats-a-rune.tar.gz) --- We're given two files, `the` and `main.go`. `the` is filled with some odd...

rev, go

Iris-CTF-2024

07 January 2024

The Johnsons

Please socialize with the Johnson's and get off your phone. You might be quizzed on it! `nc babyrevjohnson.chal.irisc.tf 10002` [babyrevjohnson.tar.gz](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/Iris-CTF-2024/babyrevjohnson.tar.gz)...

rev, logic

Iris-CTF-2024

07 January 2024

Whats My Password

[baby] Oh no! Skat forgot their password (again)! Can you help them find it? [https://whats-my-password-web.chal.irisc.tf/](https://whats-my-password-web.chal.irisc.tf/) [whats-my-password.tar.gz](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/Iris-CTF-2024/whats-my-password.tar.gz) --- We're given a...

web, sqli, union

UofT-CTF-2024

15 January 2024

Clever Thinking

I think that Diffie-Hellman is better with some curves, maybe elliptic ones. Let's share a secret! Wrap the secret (which...

crypto, ecc, smarts-attack

UofT-CTF-2024

15 January 2024

Piano Man

Windy, a piano prodigy, believes that RSA encryption may not provide sufficient security to safeguard his invaluable piano mastery secrets....

crypto, rsa

UofT-CTF-2024

15 January 2024

Repeat

I'm a known repeat offender when it comes to bad encryption habits. But the secrets module is secure, so you'll...

crypto, xor

UofT-CTF-2024

15 January 2024

Enable Me

You've received a confidential document! Follow the instructions to unlock it. Note: This is not malware Author: SteakEnthusiast [invoice.docm](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/UofT-CTF-2024/invoice.docm) ---...

forensics, microsoft-office

UofT-CTF-2024

15 January 2024

Secret Message 1

We swiped a top-secret file from the vaults of a very secret organization, but all the juicy details are craftily...

forensics

UofT-CTF-2024

15 January 2024

UofT CTF 2024

[](https://ctftime.org/event/2219) Placement: #175/1225 --- ## Thoughts: Didn't have as much time to play this one, but still had fun! Crypto...

UofT-CTF-2024

UofT-CTF-2024

15 January 2024

Babys First Iot Flag 1

See introduction for complete context. Part 1 - Here is an FCC ID, Q87-WRT54GV81, what is the frequency in MHz...

iot, fcc-lookup

UofT-CTF-2024

15 January 2024

Babys First Iot Flag 2

See introduction for complete context. Part 2 - What company makes the processor for this device? [https://fccid.io/Q87-WRT54GV81/Internal-Photos/Internal-Photos-861588](https://fccid.io/Q87-WRT54GV81/Internal-Photos/Internal-Photos-861588). Submit the answer...

iot, reverse-image-search

UofT-CTF-2024

15 January 2024

Babys First Pyjail

@windex told me that jails should be sourceless. So no source for you. Author: SteakEnthusiast `nc 35.226.249.45 5000` --- We're...

jail, pyjail, blacklist

UofT-CTF-2024

15 January 2024

Out Of The Bucket

Check out my flag website! Author: windex [https://storage.googleapis.com/out-of-the-bucket/src/index.html](https://storage.googleapis.com/out-of-the-bucket/src/index.html) --- We're given a [website](https://storage.googleapis.com/out-of-the-bucket/src/index.html) Checking out the website reveals two images...

misc, Google-storage

UofT-CTF-2024

15 January 2024

Flying High

I'm trying to find a flight I took back in 2012. I forgot the airport and the plane, but I...

osint

UofT-CTF-2024

15 January 2024

Basic Overflow

This challenge is simple. It just gets input, stores it to a buffer. It calls gets to read input, stores...

pwn, ret2win, buffer-overflow

UofT-CTF-2024

15 January 2024

Patched Shell

Okay, okay. So you were smart enough to do basic overflow huh... Now try this challenge! I patched the shell...

pwn, ret2win, buffer-overflow

Dice-CTF-Quals-2024

04 February 2024

Winter

A simple implementation of the Winternitz signature scheme. `nc mc.ax 31001` [server.py](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/Dice-CTF-Quals-2024/server.py) --- We're provided a single file, `server.py`: ```py...

crypto, winternitz, signature

Dice-CTF-Quals-2024

04 February 2024

Dice CTF Quals 2024

[](https://ctftime.org/event/2217) Placement: #167/1040 overall, #7/50 high school --- ## Thoughts: Didn't dedicate a ton of time to this, but some...

Dice-CTF-Quals-2024

Dice-CTF-Quals-2024

04 February 2024

Zshfuck

may your code be under par. execute the getflag binary somewhere in the filesystem to win `nc mc.ax 31774` [jail.zsh](https://gthub.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/Dice-CTF-Quals-2024/jail.zshs)...

misc, jail, zsh

Dice-CTF-Quals-2024

04 February 2024

Dicedicegoose

Follow the leader. [ddg.mc.ax](https://ddg.mc.ax/) --- Visit the site. Seems like some sort of game. Heading to Chrome Dev Tools with...

web, inspect

0xL4ugh-CTF-2024

10 February 2024

Poison

Author : mindFlayer02 [source.sage](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/0xL4ugh-CTF-2024/source.sage) [out.txt](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/0xL4ugh-CTF-2024/out.txt) --- We are provided a sage source file and an output file. Here's the source:...

crypto, elliptic-curve

0xL4ugh-CTF-2024

10 February 2024

Rsa Gcd

I think i might leaked something but i dont know what Author : Bebo07 [chall2.txt](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/0xL4ugh-CTF-2024/chall2.txt) [chall2.py](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/0xL4ugh-CTF-2024/chall2.py) --- We're given a...

crypto, rsa, gcd

0xL4ugh-CTF-2024

10 February 2024

0xL4ugh CTF 2024

[](https://ctftime.org/event/2216) Placement: #98/614 --- ## Thoughts: First time playing with a team (reCAPTCHA the Flag). Unfortunately, the other members didn't...

0xL4ugh-CTF-2024

Vishwa-CTF-2024

03 March 2024

Bitbane Cryptic Chaos

Once again, Mr. David made a blunder by encrypting some confidential data and deleting the original file. Can you help...

crypto, brute-force

Vishwa-CTF-2024

03 March 2024

Intellectual Heir

You received a package, and you got to know that you are the descendant of RIADSH. There are four files...

crypto, rsa

Vishwa-CTF-2024

03 March 2024

Lets Smother The King

In my friend circle, Mr. Olmstead and Mr. Ben always communicate with each other through a secret code language that...

crypto, esoteric-language

Vishwa-CTF-2024

03 March 2024

Poly Fun

Its a simple symmetric key encryption, I am sure you will be able to solve it (what do you mean...

crypto

Vishwa-CTF-2024

03 March 2024

Tevyat Tales

All tavern owners in Mondstadt are really worried because of the frequent thefts in the Dawn Winery cellars. The Adventurers’...

crypto, decoder, enigma

Vishwa-CTF-2024

03 March 2024

Vishwa CTF 2024

[](https://ctftime.org/event/2272) Placement: #116/1039 --- ## Thoughts: 2nd event with team reCAPTCHA the Flag! Only looked at the crypto category for...

Vishwa-CTF-2024

Wolv-CTF-2024

19 March 2024

Crypto Two Time Pad

One-time pads are perfectly information-theoretically secure, so I should be safe, right? [chall.py](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/Wolv-CTF-2024/beginner/chall.py) [eFlag.bmp](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/Wolv-CTF-2024/beginner/eFlag.bmp) [eWolverine.bmp](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/Wolv-CTF-2024/beginner/eWolverine.bmp) --- We're provided a Python...

beginner, crypto, otp

Wolv-CTF-2024

19 March 2024

Crypto Yors Truly

I have encrypted some text but it seems I have lost the key! Can you find it? [yors-truly.py](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/Wolv-CTF-2024/beginner/yors-truly.py) --- We're...

beginner, crypto, xor

Wolv-CTF-2024

19 March 2024

Forensics Hidden Data

WOLPHV sent me this file. Not sure what to comment about it [wctf_evil.jpg](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/Wolv-CTF-2024/beginner/wctf_evil.jpg) --- Run `strings wctf_evil.jpg | grep "wctf"`....

beginner, forensics, strings

Wolv-CTF-2024

19 March 2024

Osint Redditor

Someone told me WolvSec has a Reddit account. I wonder if they left a flag there... --- Search `wolvsec reddit`...

beginner, osint

Wolv-CTF-2024

19 March 2024

Pwn Babypwn

Just a little baby pwn. `nc babypwn.wolvctf.io 1337 ` [babypwn](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/Wolv-CTF-2024/beginner/babypwn) [babypwn.c](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/Wolv-CTF-2024/beginner/babypwn.c) --- We're provided a binary ELF and a C...

beginner, pwn, buffer-overflow

Wolv-CTF-2024

19 March 2024

Pwn Babypwn2

A harder babypwn. `nc babypwn2.wolvctf.io 1337 ` [babypwn2](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/Wolv-CTF-2024/beginner/babypwn2) [babypwn2.c](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/Wolv-CTF-2024/beginner/babypwn2.c) --- We're provided a binary ELF and a C source file....

beginner, pwn, buffer-overflow, ret2win, gets

Wolv-CTF-2024

19 March 2024

Rev Babyre

Just a wee-little baby re challenge. [babyre](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/Wolv-CTF-2024/beginner/babyre) --- No rev required! Run `strings babyre | grep "wctf"` to get the...

beginner, rev, strings

Wolv-CTF-2024

19 March 2024

Rev Shredded

We encoded a flag, and to make sure that pesky interlopers couldn't reverse it, we shredded the encoding code. Note:...

beginner, rev, brute-force, byte-by-byte

Wolv-CTF-2024

19 March 2024

Web The Gauntlet

Can you survive the gauntlet? 10 mini web challenges are all that stand between you and the flag. Note: Automated...

beginner, web

Wolv-CTF-2024

19 March 2024

Blocked 1

The WOLPHV group (yes, this is an actual article) group encrypted our files, but then blocked us for some reason....

crypto, aes, aes-cbc, oracle

Wolv-CTF-2024

19 March 2024

Blocked 2

We managed to log into doubledelete's email server. Hopefully this should give us some leads... `nc blocked2.wolvctf.io 1337` [server.py](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/Wolv-CTF-2024/crypto/blocked-2/server.py) ---...

crypto, aes, oracle, roll-your-own

Wolv-CTF-2024

19 March 2024

Limited 1

It's pretty easy to find random integers if you know the seed, but what if every second has a different...

crypto, random

Wolv-CTF-2024

19 March 2024

Limited 2

I was AFK when the flag was being encrypted, can you help me get it back? [NY_chal_time.py](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/Wolv-CTF-2024/crypto/limited-2/NY_chal_time.py) --- We're provided...

crypto, random, time

Wolv-CTF-2024

19 March 2024

Tag Series 1

Don't worry, the interns wrote this one. `nc tagseries1.wolvctf.io 1337` [chal.py](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/Wolv-CTF-2024/crypto/tag-series-1/chal.py) --- We're provided a Python source: ```py import sys...

crypto, aes, aes-ecb, oracle

Wolv-CTF-2024

19 March 2024

Tag Series 3

Surely they got it right this time. `nc tagseries3.wolvctf.io 1337` [chal.py](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/Wolv-CTF-2024/crypto/tag-series-3/chal.py) --- We're provided a Python source file: ```py import...

crypto, hash, sha1, length-extension-attack

Wolv-CTF-2024

19 March 2024

Wolv CTF 2024

[](https://ctftime.org/event/2240) Placement: #88/622 --- ## Thoughts: Didn't have too much time to do this CTF, especially since I was heading...

Wolv-CTF-2024

Wolv-CTF-2024

19 March 2024

Made Sense

i couldn't log in to my server so my friend kindly spun up a server to let me test makefiles....

misc, jail, makefile

Wolv-CTF-2024

19 March 2024

Wolphv I Reconaissance

A new ransomware group you may have heard about has emerged: WOLPHV There's already been reports of their presence in...

osint

Jersey-CTF-IV-2024

25 March 2024

Aces Aes

- The attached files were recovered from an attack committed by the malicious AI named RB. - The first file...

crypto, aes, osint

Jersey-CTF-IV-2024

25 March 2024

Adversary

You have intercepted an encrypted message from the RB back to Dr. Tom!!!! The component values of Dr. Tom's public...

crypto, rsa

Jersey-CTF-IV-2024

25 March 2024

Attn Agents

We heard a distress call and received a transmission. Only this text came through. You better take a look at...

crypto, caesar

Jersey-CTF-IV-2024

25 March 2024

Mutant Mayhem

To prevent the RB from impersonating any communications coming from you to our team, we need to employ an extremely...

crypto, ecc, secp256k1, signature

Jersey-CTF-IV-2024

25 March 2024

Vibrations

While managing some of our thermal systems, we noticed unusual behavior. We collected the network traffic, see if you can...

forensics, network, wireshark, tcp, modbus

Jersey-CTF-IV-2024

25 March 2024

Jersey CTF IV 2024

[](https://ctftime.org/event/2230) Placement: #12/520 --- ## Thoughts: TL;DR: I got trolled by crypto but clutched on osint. Played with reCAPTCHA the...

Jersey-CTF-IV-2024

Jersey-CTF-IV-2024

25 March 2024

Cyber Daddy

We're still trying to figure out who tom's new friend is. Did you dig into them from the forums? They...

osint, instagram

Jersey-CTF-IV-2024

25 March 2024

The Golden Falcon And The Rugged Lands

- Okay, this is weird. They had a whole forum going. - There must be something worthwhile in there. We...

osint

Texsaw-CTF-2024

25 March 2024

Freaky Flags

Password manager? I store all of mine in image form. [freakyFlags.png](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/Texsaw-CTF-2024/freakyFlags.png) --- Import the image into MS Paint or any...

crypto, rgb

Texsaw-CTF-2024

25 March 2024

Texsaw CTF 2024

[](https://ctftime.org/event/2281) Placement: #15/410 --- ## Thoughts: TL;DR: Crypto challenges were... questionable. Played with reCAPTCHA the Flag!

Texsaw-CTF-2024

Texsaw-CTF-2024

25 March 2024

Prison Italiano

You've been locked in the worst prison imaginable: one without any meatballs! To escape the prison, you must read the...

misc, pyjail

Texsaw-CTF-2024

25 March 2024

Geo Location

Find what street this picture was taken from. Format the flag as the following: The street name in all caps...

osint

Texsaw-CTF-2024

25 March 2024

Sherlock

I need to study for a class but the quizlet I'm using has jumbled up answers that just don't make...

osint, vigenere

Texsaw-CTF-2024

25 March 2024

Ask And It Shall Be Given To You

The flag is at 3.23.56.243:9008. Unfortunately it seems like the site is down right now :( . Maybe you can...

web, robots.txt, error, post

Texsaw-CTF-2024

25 March 2024

Extreme Security

We are at 3.23.56.243:9003. We are so secure that we only allow requests from our own origin to access secret...

web, headers

Texsaw-CTF-2024

25 March 2024

Over 9000

Help Goku get over 9000 energy to defeat his enemy Vegeta and save the world. 3.23.56.243:9005 --- Visit the site....

web, post

UT-CTF-2024

01 April 2024

Beginner Anti Dcode.fr

I've heard that everyone just uses dcode.fr to solve all of their crypto problems. Shameful, really. This is really just...

crypto, caesar

UT-CTF-2024

01 April 2024

Cryptordle

Just guess the word in 6 tries. What do you mean it's hard? By oops (former ISSS officer) Officer in...

crypto, math

UT-CTF-2024

01 April 2024

Numbers Go Brr 2

A spiritual successor the first. By jocelyn (@jocelyn3270 on discord) `nc betta.utctf.live 2435` [main-brr2.py](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/UT-CTF-2024/main-brr2.py) --- We're provided a Python source...

crypto, random, aes, oracle

UT-CTF-2024

01 April 2024

Numbers Go Brr

I wrote an amazing encryption service. It is definitely flawless, so I'll encrypt the flag and give it to you....

crypto, random, aes, oracle

UT-CTF-2024

01 April 2024

Rsa 256

Based on the military-grade encryption offered by AES-256, RSA-256 will usher in a new era of cutting-edge security... or at...

crypto, rsa

UT-CTF-2024

01 April 2024

Simple Signature

The s in rsa stands for secure. By alex (@kyrili : not the isss officer - someone y'all don't know)...

crypto, signature, forgery

UT-CTF-2024

01 April 2024

Gibberish

Help! I'm trying to spy on my lover but they're not typing in any language I'm familiar with! By mzone...

forensics, network, stenography

UT-CTF-2024

01 April 2024

UT CTF 2024

[](https://ctftime.org/event/2302) Placement: #8/854 --- ## Thoughts: Best CTF yet with my team reCAPTCHA the Flag! I completed all of the...

UT-CTF-2024

UT-CTF-2024

01 April 2024

Ccv

I've got some credit cards but I don't which ones are valid. Where did I get them? Uh, that's not...

misc, credit-cards

UMD-CTF-2024

28 April 2024

Triple Des

Before the Kwisatz Haderach, the Bene Gesserit used this oracle to predict the future. `nc challs.umdctf.io 32333` [tripledes.py](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/UMD-CTF-2024/tripledes.py) --- We're...

crypto, des, 3des, padding-oracle

UMD-CTF-2024

28 April 2024

UMD CTF 2024

[](https://ctftime.org/event/2323) Placement: #28/562 --- ## Thoughts: Another CTF with reCAPTCHA the Flag! Solved 2 crypto and 1 pwn. The other...

UMD-CTF-2024

UMD-CTF-2024

28 April 2024

Mentat Question

Thufir Hawat is ready to answer any and all questions you have. Unless it's not about division... `nc challs.umdctf.io 32300`...

pwn, buffer-overflow, gets, format-string, ret2win, PIE

squ1rrel-CTF-2024

28 April 2024

Lazy Rsa

Generating primes is too hard, but I did find a couple posted online! [lazyrsa.txt](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/squ1rrel-CTF-2024/lazyrsa.txt) --- The provided txt file just...

crypto, rsa, factordb

squ1rrel-CTF-2024

28 April 2024

Partial Rsa

Hmm? What's wrong with using the same flag format again? Whisper it in my ear so they don't hear. [partialrsa.txt](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/squ1rrel-CTF-2024/partialrsa.txt)...

crypto, rsa, coppersmith, stereotyped-message-attack

squ1rrel-CTF-2024

28 April 2024

Rsa Rsa Rsa

I had something so important to say that I just had to tell three of my friends! [rsarsarsa.txt](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/squ1rrel-CTF-2024/rsarsarsa.txt) --- Here's...

crypto, rsa, hastad-broadcast-attack

squ1rrel-CTF-2024

28 April 2024

Squ1rrel Lottery

Welcome to the squ1rrel lottery! 9 winning numbers will be selected, and if any of your tickets share 3 numbers...

crypto

squ1rrel-CTF-2024

28 April 2024

Squ1rrel Treasury

We recently opened a new bank, our exchange rate is pretty poor though `nc treasury.squ1rrel-ctf-codelab.kctf.cloud 1337` [chall.py](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/squ1rrel-CTF-2024/chall.py) --- Here's chall.py:...

crypto, aes, cbc

squ1rrel-CTF-2024

06 May 2024

squ1rrel CTF 2024

[](https://ctftime.org/event/2370) Placement: #6/378 All, #2/44 Student Winnings: $150 --- ## Thoughts: Another CTF with reCAPTCHA the Flag! Cleared crypto (the...

squ1rrel-CTF-2024

TJ-CTF-2024

19 May 2024

Account Leak

Uncrackable password? I thought this was a CTF; get me my friends minecraft password pls i have an uncrackable password...

crypto, rsa

TJ-CTF-2024

19 May 2024

Alkane

I hate standing in line for gas.... [output.txt](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/TJ-CTF-2024/alkane/output.txt) [main.py](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/TJ-CTF-2024/alkane/main.py) --- Here's the Python source: ```py schedule = # ommitted because...

crypto, matrix

TJ-CTF-2024

19 May 2024

Assume

assume for the sake of contradiction that pet the catloe [main.sage](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/TJ-CTF-2024/assume/main.sage) [log.txt](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/TJ-CTF-2024/assume/log.txt) --- Here's the sage source: ```py import random...

crypto

TJ-CTF-2024

19 May 2024

Hulksmash

my friends password is keysmash.... :(... i got some of his old keysmashes tho.... he types kinda funny.... [output.txt](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/TJ-CTF-2024/hulksmash/output.txt) [keysmashes.txt](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/TJ-CTF-2024/hulksmash/keysmashes.txt)...

crypto

TJ-CTF-2024

19 May 2024

Iodomethane

AINT NO HILL HIGH ENOUGH.... [out.txt](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/TJ-CTF-2024/iodomethane/out.txt) [main.py](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/TJ-CTF-2024/iodomethane/main.py) --- Here's the Python source: ```py import secrets flag = open("flag.txt", "r").read().strip() print(flag)...

crypto, matrix

TJ-CTF-2024

19 May 2024

Lightweight Crypto Guard System

They said OTPs were too simple. [out.txt](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/TJ-CTF-2024/lightweight-crypto-guard-system/out.txt) [encode.py](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/TJ-CTF-2024/lightweight-crypto-guard-system/encode.py) --- Before you begin reading this writeup, I highly, highly recommend you...

crypto, lcg

TJ-CTF-2024

19 May 2024

Weird Crypto

weird crypto hmmm [a.py](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/TJ-CTF-2024/weird-crypto/a.py) [output.txt](https://github.com/Nightxade/ctf-writeups/blob/master/assets/CTFs/TJ-CTF-2024/weird-crypto/output.txt) --- Here's the Python source: ```py from math import lcm from Crypto.Util.number import bytes_to_long, getPrime...

crypto, rsa, wiener

TJ-CTF-2024

19 May 2024

TJ CTF 2024

[](https://ctftime.org/event/2321) Placement: #5/19 HS, #25/518 all --- ## Thoughts: Played with reCAPTCHA the Flag! Lots of crypto challs, felt quite...

TJ-CTF-2024

BCA-CTF-2024

12 June 2024

Cha Cha Slide

I made this cool service that lets you protect your secrets with state-of-the-art encryption. It's so secure that we don't...

crypto, chacha20

BCA-CTF-2024

12 June 2024

Cinnamon Dynamics

Cinnamon Dynamics, an innovative technology company, provides a service for the public to execute short scripts to query some limited...

crypto, sha256, length-extension-attack

BCA-CTF-2024

12 June 2024

Encryptor Shop

After realizing how insecure the systems of many companies are (they're always getting hacked), I decided to start offering Encryption...

crypto, rsa, gcd

BCA-CTF-2024

12 June 2024

Rad Be Damned

My friend seems to be communicating something but I can't make out anything. Why do we live so close to...

crypto, error-checking

BCA-CTF-2024

12 June 2024

Rsa Encrypter

I made an rsa encrypter to send my messages but it seems to be inconsistent... `nc challs.bcactf.com 31452` [rsa_encrypter.py](https://github.com/Nightxade/ctf-writeups/tree/master/assets/CTFs/BCA-CTF-2024/rsa_encrypter.py) ---...

crypto, rsa, hastad-broadcast-attack

BCA-CTF-2024

12 June 2024

Superstitious 2

My client is a bit picky with the primes they are willing to use... (Sequel from BCACTF 4.0) [superstitious-2.py](https://github.com/Nightxade/ctf-writeups/tree/master/assets/CTFs/BCA-CTF-2024/superstitious-2.py) [superstitious-2.txt](https://github.com/Nightxade/ctf-writeups/tree/master/assets/CTFs/BCA-CTF-2024/superstitious-2.txt)...

crypto, rsa, branch-and-prune

BCA-CTF-2024

12 June 2024

Talk To Echo

Echo is lonely and would like to talk `nc challs.bcactf.com 31755` [echo.py](https://github.com/Nightxade/ctf-writeups/tree/master/assets/CTFs/BCA-CTF-2024/echo.py) --- Here's the source code: ```py from random...

crypto, ecc, invalid-curve-attack

BCA-CTF-2024

12 June 2024

Time Skip

One of our problem writers got sent back in time! We found a piece a very very old piece of...

crypto, scytale

BCA-CTF-2024

12 June 2024

Vinegar Times 3

We can't speak French and just say what we see. We also don't know what underscores are add them yourself....

crypto, vigenere

BCA-CTF-2024

12 June 2024

BCA CTF 2024

[](https://ctftime.org/event/2274) Placement: #5/823 overall, #2/139 high school --- ## Thoughts: More prize money for reCAPTCHA the Flag! Dedicated a lot...

BCA-CTF-2024

UIUCTF-2024

02 July 2024

Determined

"It is my experience that proofs involving matrices can be shortened by 50% if one throws the matrices out." Emil...

crypto, rsa, gcd

UIUCTF-2024

02 July 2024

Groups

My friend told me that cryptography is unbreakable if moduli are Carmichael numbers instead of primes. I decided to use...

crypto, carmichael, dlp

UIUCTF-2024

02 July 2024

Naptime

I'm pretty tired. Don't leak my flag while I'm asleep. [pub.txt](https://github.com/Nightxade/ctf-writeups/tree/master/assets/CTFs/UIUCTF-2024/nap-pub.txt) [enc_dist.sage](https://github.com/Nightxade/ctf-writeups/tree/master/assets/CTFs/UIUCTF-2024/nap-enc_dist.sage) --- Here's the source Sage file: ```py from...

crypto, knapsack, merkle-hellman, byte-by-byte

UIUCTF-2024

02 July 2024

Snore Signatures

These signatures are a bore! `ncat --ssl snore-signatures.chal.uiuc.tf 1337` [chal.py](https://github.com/Nightxade/ctf-writeups/tree/master/assets/CTFs/UIUCTF-2024/snore-chal.py) --- Here's the Python source: ```py #!/usr/bin/env python3 from Crypto.Util.number...

crypto, schnorr-signature, forgery

UIUCTF-2024

02 July 2024

Without A Trace

Gone with the wind, can you find my flag? `ncat --ssl without-a-trace.chal.uiuc.tf 1337` [server.py](https://github.com/Nightxade/ctf-writeups/tree/master/assets/CTFs/UIUCTF-2024/trace-server.py) --- Here's the Python source: ```py...

crypto

UIUCTF-2024

02 July 2024

UIUCTF 2024

[](https://ctftime.org/event/2275) Placement: #80/959 --- ## Thoughts: i need a good nap after crypto/naptime. sleep-deprivation levels at an all-time high. In...

UIUCTF-2024