Crypto CTF 2019
33 challenges with 78 published community solutions between them. Solution links go to CTFtime’s task page, which aggregates every writeup for a challenge - individual blog posts rot, the aggregator does not.
Full task list on CTFtimeUncategorised13
The upstream scoreboard did not say, so neither do we.
Aron(maybe intended)
2 official solutionsAlso written up in: Ariana1729/CTF-Writeups, Ariana1729/CTF-Writeups
Aron(unintended)
2 official solutionsAlso written up in: Ariana1729/CTF-Writeups, Ariana1729/CTF-Writeups
Cipher
2 official solutionsAlso written up in: utisss/ctf, utisss/ctf
Also written up in: google/google-ctf, google/google-ctf
Plain
2 official solutionsAlso written up in: utisss/ctf, utisss/ctf
Also written up in: arty-hlr/CTF-writeups
Also written up in: alex-bellon/ctf-writeups
Permutations
1 official solutionAlso written up in: arty-hlr/CTF-writeups
Plaintext
1 official solutionAlso written up in: utisss/ctf
Project Dc
1 official solutionAlso written up in: google/google-ctf
Also written up in: utisss/ctf
Script
1 official solutionAlso written up in: killua4564/2019-Crypto-CTF
Secrets
1 official solutionAlso written up in: google/google-ctf
Cryptography12
Recover a plaintext or a key from something that was supposed to protect it. In practice: identify the scheme, find the parameter the author got wrong, exploit it.
Also written up in: Ariana1729/CTF-Writeups, pcw109550/write-up, Ariana1729/CTF-Writeups
- rsa
Same technique in picoCTF: It's Not My Fault 2, StegoRSA, john_pollard
Also written up in: Ariana1729/CTF-Writeups, Ariana1729/CTF-Writeups, arty-hlr/CTF-writeups
- rsa-like
- crypto
Same technique in picoCTF: It's Not My Fault 2, StegoRSA, john_pollard
Also written up in: pcw109550/write-up, pcw109550/write-up
- prime
- crypto
- rsa
Same technique in picoCTF: It's Not My Fault 2, StegoRSA, john_pollard
Also written up in: pcw109550/write-up, arty-hlr/CTF-writeups
- factoring
- rsa
Same technique in picoCTF: It's Not My Fault 2, StegoRSA, john_pollard
Also written up in: arty-hlr/CTF-writeups, arty-hlr/CTF-writeups
- crypto
Same technique in picoCTF: It's Not My Fault 2, StegoRSA, AES-ABC
Also written up in: xuanxuanblingbling.github.io
- fermat
- guessing
- rsa
Same technique in picoCTF: It's Not My Fault 2, StegoRSA, john_pollard
- ecc
Same technique in picoCTF: It's Not My Fault 2, StegoRSA, AES-ABC
Rabin
1 official solutionAlso written up in: xuanxuanblingbling.github.io
Also written up in: xuanxuanblingbling.github.io
- polynomial
- rsa
Same technique in picoCTF: It's Not My Fault 2, StegoRSA, john_pollard
Vigenere
1 official solutionAlso written up in: xuanxuanblingbling.github.io
Misc7
Everything that fits no other box: esolangs, puzzles, scripting exercises, and the jail escapes that have not yet earned their own category.
Also written up in: pcw109550/write-up, Ariana1729/CTF-Writeups, arty-hlr/CTF-writeups, meowmeowxw.gitlab.io
- modular-arithmetic
Same technique in picoCTF: PW Crack 2, Permissions, Specialer
Also written up in: pcw109550/write-up, Ariana1729/CTF-Writeups, killua4564/2019-Crypto-CTF, pcw109550/write-up, Ariana1729/CTF-Writeups
- number_theory
Same technique in picoCTF: PW Crack 2, Permissions, Specialer
Also written up in: Ariana1729/CTF-Writeups, pcw109550/write-up, Ariana1729/CTF-Writeups
- linear_algebra
Same technique in picoCTF: PW Crack 2, Permissions, Specialer
Also written up in: bananamafia.dev
- base64
- rotated
Same technique in picoCTF: Bases, repetitions, PW Crack 2
Also written up in: Ariana1729/CTF-Writeups, pcw109550/write-up
- png
- xor
Same technique in picoCTF: PW Crack 2, Permissions, Specialer
Also written up in: Ariana1729/CTF-Writeups, Ariana1729/CTF-Writeups
- programming
Same technique in picoCTF: PW Crack 2, Permissions, Specialer
- secret-sharing
Same technique in picoCTF: PW Crack 2, Permissions, Specialer
Reverse engineering1
Work out what a compiled program does without its source, then work backwards from the check to the input that passes it.
Also written up in: g-0-p-h-e-r/CTF