The digital computer age has enriched the field of cryptography with the development of complex ciphers. In contrast to classical ciphers, which can only encrypt language texts, the new ciphers were able to encrypt any kind of data represented in binary form. Extensive cryptographic research in academia have led to the development of symmetric-key cryptography methods such as the Data Encryption Standard and public-key cryptography methods such the Diffie-Hellman key exchange and the RSA algorithm. With these new tools, cryptography has become an essential tool in communications, computer networks, computer security, and national security.