Crypto CTFs Tricks

Online Hashes DBs

• Google it

• http://hashtoolkit.com/reverse-hash?hash=4d186321c1a7f0f354b297e8914ab240

• https://www.onlinehashcrack.com/

• https://crackstation.net/

• https://md5decrypt.net/

• https://www.onlinehashcrack.com

• https://gpuhash.me/

• https://hashes.org/search.php

• https://www.cmd5.org/

• https://hashkiller.co.uk/Cracker/MD5

• https://www.md5online.org/md5-decrypt.html

Encoders

Most of encoded data can be decoded with these 2 ressources:

• https://www.dcode.fr/tools-list

• https://gchq.github.io/CyberChef/

Substitution Autosolvers

• https://www.boxentriq.com/code-breaking/cryptogram
• https://quipqiup.com/ - Very good !

Caesar - ROTx Autosolvers

• https://www.nayuki.io/page/automatic-caesar-cipher-breaker-javascript

Atbash Cipher

• http://rumkin.com/tools/cipher/atbash.php

Similar to BASE64

Check all bases with: https://github.com/mufeedvh/basecrack

• Base32 [A-Z2-7=]

  • NBXWYYLDMFZGCY3PNRQQ====

• Base58 [123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz]

  • 2yJiRg5BF9gmsU6AC

• Base62 [0-9A-Za-z]

  • g2AextRZpBKRBzQ9

• Base64 [A-Za-z0-9+/=]

  • aG9sYWNhcmFjb2xh

• Base85 --> Like Ascii85

• ATOM-128 [/128GhIoPQROSTeUbADfgHijKLM+n0pFWXY456xyzB7=39VaqrstJklmNuZvwcdEC]

  • MIc3KiXa+Ihz+lrXMIc3KbCC

• HAZZ15 [HNO4klm6ij9n+J2hyf0gzA8uvwDEq3X1Q7ZKeFrWcVTts/MRGYbdxSo=ILaUpPBC5]

  • DmPsv8J7qrlKEoY7

• MEGAN35 [3GHIJKLMNOPQRSTUb=cdefghijklmnopWXYZ/12+406789VaqrstuvwxyzABCDEF5]

  • kLD8iwKsigSalLJ5

• ZONG22 [ZKj9n+yf0wDVX1s/5YbdxSo=ILaUpPBCHg8uvNO4klm6iJGhQ7eFrWczAMEq3RTt2]

  • ayRiIo1gpO+uUc7g

• ESAB46 []

  • 3sHcL2NR8WrT7mhR

• MEGAN45 []

  • kLD8igSXm2KZlwrX

• TIGO3FX []

  • 7AP9mIzdmltYmIP9mWXX

• TRIPO5 []

  • UE9vSbnBW6psVzxB

• FERON74 []

  • PbGkNudxCzaKBm0x

• GILA7 []

  • D+nkv8C1qIKMErY1

• Citrix CTX1 []

  • MNGIKCAHMOGLKPAKMMGJKNAINPHKLOBLNNHILCBHNOHLLPBK

http://k4.cba.pl/dw/crypo/tools/eng_atom128c.html - 404 Dead: https://web.archive.org/web/20190228181208/http://k4.cba.pl/dw/crypo/tools/eng_hackerize.html

HackerizeXS [╫Λ↻├☰┏]

╫☐↑Λ↻Λ┏Λ↻☐↑Λ

• http://k4.cba.pl/dw/crypo/tools/eng_hackerize.html - 404 Dead: https://web.archive.org/web/20190228181208/http://k4.cba.pl/dw/crypo/tools/eng_hackerize.html

Morse

.... --- .-.. -.-. .- .-. .- -.-. --- .-.. .-

• http://k4.cba.pl/dw/crypo/tools/eng_morse-encode.html - 404 Dead: https://gchq.github.io/CyberChef/

UUencoder

begin 644 webutils_pl
M2$],04A/3$%(3TQ!2$],04A/3$%(3TQ!2$],04A/3$%(3TQ!2$],04A/3$%(
M3TQ!2$],04A/3$%(3TQ!2$],04A/3$%(3TQ!2$],04A/3$%(3TQ!2$],04A/
F3$%(3TQ!2$],04A/3$%(3TQ!2$],04A/3$%(3TQ!2$],04A/3$$`
`
end

• http://www.webutils.pl/index.php?idx=uu

XXEncoder

begin 644 webutils_pl
hG2xAEIVDH236Hol-G2xAEIVDH236Hol-G2xAEIVDH236Hol-G2xAEIVDH236
5Hol-G2xAEE++
end

• www.webutils.pl/index.php?idx=xx

YEncoder

=ybegin line=128 size=28 name=webutils_pl
ryvkryvkryvkryvkryvkryvkryvk
=yend size=28 crc32=35834c86

• http://www.webutils.pl/index.php?idx=yenc

BinHex

(This file must be converted with BinHex 4.0)
:#hGPBR9dD@acAh"X!$mr2cmr2cmr!!!!!!!8!!!!!-ka5%p-38K26%&)6da"5%p
-38K26%'d9J!!:

• http://www.webutils.pl/index.php?idx=binhex

ASCII85

<~85DoF85DoF85DoF85DoF85DoF85DoF~>

• http://www.webutils.pl/index.php?idx=ascii85

Dvorak keyboard

drnajapajrna

• https://www.geocachingtoolbox.com/index.php?lang=en&page=dvorakKeyboard

A1Z26

Letters to their numerical value

8 15 12 1 3 1 18 1 3 15 12 1

Affine Cipher Encode

Letter to num (ax+b)%26 (a and b are the keys and x is the letter) and the result back to letter

krodfdudfrod

SMS Code

Multitap replaces a letter by repeated digits defined by the corresponding key code on a mobile phone keypad (This mode is used when writing SMS). For example: 2=A, 22=B, 222=C, 3=D... You can identify this code because you will see several numbers repeated.

You can decode this code in: https://www.dcode.fr/multitap-abc-cipher

Bacon Code

Substitude each letter for 4 As or Bs (or 1s and 0s)

00111 01101 01010 00000 00010 00000 10000 00000 00010 01101 01010 00000
AABBB ABBAB ABABA AAAAA AAABA AAAAA BAAAA AAAAA AAABA ABBAB ABABA AAAAA

Runes

Compression

Raw Deflate and Raw Inflate (you can find both in Cyberchef) can compress and decompress data without headers.

Easy Crypto

XOR - Autosolver

• https://wiremask.eu/tools/xor-cracker/

Bifid

A keywork is needed

fgaargaamnlunesuneoa

Vigenere

A keywork is needed

wodsyoidrods

• https://www.guballa.de/vigenere-solver
• https://www.dcode.fr/vigenere-cipher
• https://www.mygeocachingprofile.com/codebreaker.vigenerecipher.aspx

Strong Crypto

Fernet

2 base64 strings (token and key)

Token:
gAAAAABWC9P7-9RsxTz_dwxh9-O2VUB7Ih8UCQL1_Zk4suxnkCvb26Ie4i8HSUJ4caHZuiNtjLl3qfmCv_fS3_VpjL7HxCz7_Q==

Key:
-s6eI5hyNh8liH7Gq0urPC-vzPgNnxauKvRO4g03oYI=

• https://asecuritysite.com/encryption/ferdecode

Samir Secret Sharing

A secret is splitted in X parts and to recover it you need Y parts (Y <=X).

8019f8fa5879aa3e07858d08308dc1a8b45
80223035713295bddf0b0bd1b10a5340b89
803bc8cf294b3f83d88e86d9818792e80cd

http://christian.gen.co/secrets/

OpenSSL brute-force

• https://github.com/glv2/bruteforce-salted-openssl
• https://github.com/carlospolop/easy_BFopensslCTF

Tools

• https://github.com/Ganapati/RsaCtfTool
• https://github.com/lockedbyte/cryptovenom
• https://github.com/nccgroup/featherduster