Redpwn 2020 Crypto - worst_pw_manager
worst-pw-manager
Description
I found this in-progress password manager on a dead company's website. Seems neat.
Files
worst-pw-manager.zip
worst-pw-manager/worst-pw-manager.py
worst-pw-manager/passwords/
worst-pw-manager/passwords/0_135791.enc
…
worst-pw-manager.py wor...
Redpwn 2020 Crypto - Pseudo-key
Pseudo key
Description
Keys are not always as they seem...
Note: Make sure to wrap the plaintext with flag{} before you submit!
Files
pseudo-key-output.txt
pseudo-key.py
Lets take a quick look at the contents of pseudo-key.py
#!/usr/bin/env python3
from string import ascii_lowercase
chr_to_num = {c: i for i, c in enumerate(ascii_lowe...
Redpwn 2020 Crypto - primimity
Primitity
Description
People claim that RSA with two 1024-bit primes is secure. But I trust no one. That's why I use three 1024-bit primes.
I even created my own prime generator to be extra cautious!
Files
primimity.py
primimity-public-key.txt
Lets take a look at source primimity.py
#!/usr/bin/env python3
from Crypto.Util.number imp...
Redpwn 2020 Crypto - Itsy Bitsy
itsy-bitsy
Description
The itsy-bitsy spider climbed up the water spout...
nc 2020.redpwnc.tf 31284
Files
itsy-bitsy.py
Lets quickly take a look at now the connection works
nc 2020.redpwnc.tf 31284
Enter an integer i such that i > 0: 1
Enter an integer j such that j > i > 0: 2
Ciphertext: 0010001001011101111000001100000010000011...
Redpwn 2020 Crypto - base646464
base646464
Description
Encoding something multiple times makes it exponentially more secure!
Files
cipher.txt
generate.js
Lets take a look at generate.js, which reads
const btoa = str => Buffer.from(str).toString('base64');
const fs = require("fs");
const flag = fs.readFileSync("flag.txt", "utf8").trim();
let ret = flag;
for(let i...
Redpwn 2020 Crypto - Alien Transmissions v2
Alien-transmissions-v2
Description
The aliens are at it again! We've discovered that their communications are in base 512 and have transcribed them in base 10. However, it seems like they used XOR encryption twice with two different keys! We do have some information:
* This alien language consists of words delimitated by the character repres...
Redpwn 2020 Crypto - 4k-rsa
4k-rsa
Description
Only n00bz use 2048-bit RSA. True gamers use keys that are at least 4k bits long, no matter how many primes it takes...
Files
4k-rsa-public-key.txt which contains a n, e, c triple
Seems like there are a lot of primes in the factorization of n, since the factorization process is influenced directly by the size of prime fact...
Redpwn 2020 Crypto - 12 Shades of Redpwn
12-shades-of-redpwn
Description
Everyone's favorite guess god Tux just sent me a flag that he somehow encrypted with a color wheel!
I don't even know where to start, the wheel looks more like a clock than a cipher... can you help me crack the code?
Files
color-wheel.jpg
ciphertext.jpg “Text” XD
Lets think like a clock, and sta...
60 post articles, 8 pages.