Cryptography

Whatever happen, google is your friend. There are a lot cryptography tools online. Some of good tool are made offline like OpenSSL.

Classic cipher / Simple decoder online tool

1. ​https://quipqiup.com - quipqiup is a fast and automated cryptogram solver

2. ​https://www.base64decode.org/ - base64 decoder

3. ​https://www.urldecoder.org/ - URL decoder

4. ​https://emn178.github.io/online-tools/base32_decode.html - Base32 decoder

5. ​https://cryptii.com/ - All in one tool

6. ​https://www.guballa.de/substitution-solver - Substitution solver

7. ​https://www.guballa.de/vigenere-solver - Vigenere solver

8. ​https://rot13.com/ - Rot 1 - 25 decryptor

9. ​https://www.dcode.fr - All in one tool

10. ​http://rumkin.com/tools/cipher/ - All in one tool

11. ​http://www.unit-conversion.info/texttools/morse-code/ - Morse code decoder

12. ​https://cryptii.com/pipes/ascii85-encoding - ASCII85 decoder

Modern cryptography

1. ​https://gchq.github.io/CyberChef/ - All in one tool

2. ​https://crackstation.net/ - Crack hash

3. Cryptool

4. John the Ripper

5. Hashcat

   Cracking compressed file

6. John the Ripper - john --wordlist=/usr/share/wordlists/rockyou.txt hash.txt

7. fcrackzip - fcrackzip -D -u -p rockyou.txt filename.zip

8. Hashcat

Note: Sometime there are some challenges that require you to develop your own decryptor for that particular challenges. Just make sure you have a good scripting/programming language to solve the challenges.