1. https://github.com/kokke/tiny-AES128-C. https://github.com/kokke/tiny-AES128-C.
2. https://github.com/tarequeh/DES. https://github.com/tarequeh/DES.
3. https://tools.ietf.org/html/rfc3174. https://tools.ietf.org/html/rfc3174.
4. https://tools.ietf.org/html/rfc6234. https://tools.ietf.org/html/rfc6234.
5. https://github.com/poupou9779/z2048. https://github.com/poupou9779/z2048.