I’m SIN_GREED. I play CTFs for TamilCTF Team. In this blog I’m gonna tell about Cryptography and its methodology for solving it!
WHAT IS CRYPTOGRAPHY?
In simple words , its about encrypting a message so that no other stranger can read it. So lets see what wikipedia says…
“Cryptography, or cryptology, is the practice and study of techniques for secure communication in the presence of adversarial behavior”
Sed Wiki literally makes it difficult to understand :(
Okay, so Cryptography contains some terms. For example,
Cipher - Encrypted Text
Key - Password
That’s it ig lol
So there are variety of ciphers present in internet and their methodolgy of encrypting it. Lemme explain some of the popular ciphers!!
1) Caesar Cipher - The characters are shifted to a particular character. For example,
It contains both the direction , left as well as right.
That picture contains the Caesar cipher with Left Shift of 3!
2) Vignere Cipher - This is similar to Caesar Cipher and Polyalphabetic Cipher but it works with the help of a key!!
This link will really help you out! geeksforgeeksvignere
3) BASE CIPHER( Favourite Cipher for all) - As you all know BASE16(Hexadecimal) , BASE10(Octal) , BASE2(Binary). There is similar BASE Ciphers like that! For Example,
Base64,Base32,Base58,Base85,Base62 etc etc
4)XOR Cipher - It works on the basis of Bitwise Xor Gate
With this basics you will get an idea to solve basic Cryptography Challenges!
Okay so lets get into business!!
TIPS FOR SOLVING BASIC CHALLENGES
1) So I suggest you to use this tool Cyberchef
It literally containse tons of cipher decryption methodology and it automates!
2) Finding the correct cipher! After knowing about these basics , you will really get an idea. Mostly ciphers will be similar to it.
WHERE YOU CAN LEARN CRYPTOGRAPHY??
I have plenty of resources for it!! Dont worry!!
6) Stanford Cryptography Course
7) Cryptography with Python This is a paid course sedly :(
8) Ofcourse CTF Writeups!!!
Sed! There is no videos for learning Cryptography and to implement them!
** So what we need to do is SELF STUDY!!**
If you guys have any resources , please share it to the community! :)
I really dont know its worth to read! I’m not used to write blogs sedly! Sorry if I explained anything wrong! I’m new to this category! I just wanna contribute something to my lovely InfoSec Community!!
Hacklido is really a good initiative! Nandrigal Pala for the Developers!!
If you have any doubts or any help! Please feel free to reach me out!!