cryptography

Cryptography

Quick Start

• Is the text relatively small? a few sentences?

  • Is the text 32 characters long? Most likely an md5 hash

  • 40 characters long? Most likely a SHA1 hash

  • Are there equal signs spread out through the text, often next to each other? Probably a base64 encoded string

  • Is the text only letters, without numbers or special characters?

    • Check if it is a Caesar, Vigenere, or other type of cipher

  • Rarely, it may be a keyboard map as found in the Olympic CTF 2014

• Any hints about keys? signing? most likely RSA

##About

Cryptography is the practice and study of techniques for secure communication in the presence of third parties. - Wikipedia

In the case of CTFs, the goal is usually to crack or clone cryptographic objects or algorithms to reach the flag.

###Example

If you look around the folders in this page you should be able to find a suitable way to solve this simple cipher:

Hint: Julius Caesar's favorite cipher

kxn iye lbedec

##Sources/See More

Introduction to Cryptography