Diagram of the <a href="https://en.wikipedia.org/wiki/Feistel_cipher" class="extiw" title="en:Feistel cipher">Feistel function</a> of the <a href="https://en.wikipedia.org/wiki/Cryptomeria_cipher" class="extiw" title="en:Cryptomeria cipher">Cryptomeria cipher</a>.
Me (<a href="//commons.wikimedia.org/wiki/User:Intgr" title="User:Intgr">Intgr</a>)
Self-made (following the source code from the <a rel="nofollow" class="external text" href="http://www.4centity.com/data/tech/spec/C2_100.pdf">C2 Block Cipher Specification</a>)