Past, present, and future methods of cryptography and data encryption

Past, present, and future methods of cryptography and data encryption

• Historical cryptography 

• Rome

The earliest recorded military use of cryptography comes from Julius Caesar 2,000 years ago. Caesar, being commander of the Roman army, solved the problem of secure communication with his troops. The problem was that messengers of secret military messages were often overtaken by the enemy. Caesar developed a substitution cipher method in which he would substitute letters for different letters. Only those who knew the substitution used could decipher the secret messages. Now when the messengers were overtaken the secret messages were not exposed. This gave the Roman army a huge advantage during war. 

• Modern cryptography 

• One-Time Pad 

The "one-time pad" encryption algorithm was invented in the early 1900's, and has since been proven as unbreakable. The one-time pad algorithm is derived from a previous cipher called Vernam Cipher, named after Gilbert Vernam. The Vernam Cipher was a cipher that combined a message with a key read from a paper tape or pad. The Vernam Cipher was not unbreakable until Joseph Mauborgne recognized that if the key was completely random the cryptanalytic difficultly would be equal to attempting every possible key (Kahn 1996). Even when trying every possible key, one would still have to review each attempt at decipherment to see if the proper key was used. The unbreakable aspect of the one-time pad comes from two assumptions: the key used is completely random; and the key cannot be used more than once. The security of the one-time pad relies on keeping the key 100% secret.

The one-time pad is typically implemented by using a modular addition (XOR) to combine plaintext elements with key elements. An example of this is shown in Figure 11. The key used for encryption is also used for decryption. Applying the same key to the ciphertext results back to the plaintext. 

• Future methods of cryptography 

• Elliptic Curve Cryptography

Elliptic Curve Cryptography (ECC) has technically already been invented but is considered by the author to be a future technique of cryptography because its advantages and disadvantages are not yet fully understood. ECC is an approach to encryption that utilizes the complex nature of elliptic curves in finite fields. ECC typically uses the same types of algorithms as that of Diffie-Hellman Key Exchange and RSA Encryption. The difference is that the numbers used are chosen from a finite field defined within an elliptic curve expression.

• Resources 

• http://www.eng.utah.edu/~nmcdonal/Tutorials/EncryptionResearchReview.pdf
• http://www.studentpulse.com/articles/41/a-brief-history-of-cryptography
• http://web.itu.edu.tr/~orssi/dersler/cryptography/Chap2-1.pdf