Play & Learn With CryptoHack

CryptoHack is a fun way to learn cryptography and also acquire valuable CTF skills. Through a series of puzzles, it challenges you to break bad implementations of "modern" crypto, such as AES, RSA, and Elliptic-curves.

Although CryptoHack took its inspiration from Capture the Flag competitions, it focuses exclusively on their cryptography aspects, that is breaking ciphers, decrypting, encoding and converting between formats. Its challenges include: 

• Downloading vulnerable source code and determining how to crack the output.
• Making web requests to a server and slowly extracting confidential data.
• Connecting to a port and performing a man-in-the-middle attack on two parties trying to communicate. 

full article on i-programmer.info