Cryptography is a field in information science that was of tremendous utility in the World Wars and the years following. It deals with several critical aspects of information security by ensuring that the message sent to allies cannot be deciphered by unintended parties. Additionally, cryptography also entails being able to break the codes binding the communication between enemy factions – although it isn’t relegated only to enemies, as sometimes you wish to know what impartial parties or even allies are discussing.
In World War II, for example, a major use of cryptography involved the extremely proprietary language of the Navajo Indians. Bilingual members of the tribe were employed by the Navy as a means of secretly transmitting tactical information, and the use of languages like Choctaw, Cherokee, and Comanche made significant contributions to the war and turned the tide of battle more than once in favor of the Allies.
Despite the successes of the Native American languages as cryptographic methods, most computer scientists would argue that it could only ever be a temporary solution, since languages can be learned with time. Mathematical methods are preferred in modern times, especially given the widespread availability and power of computers. Cryptographic codes are widely available; it’s the keys to the code that are presumably difficult to break. The code is known as a cipher, and while the makeup of the cipher represents an initial level of security, the power of modern computers in the hands of an adequate cryptanalyst makes a cipher relatively easy to comprehend.
What you need, then, are secure keys, which is why most websites prompting you for personal information recommend that you fashion a strong password. The computer program into which you enter the password is the cipher (the code is either common knowledge or relatively easy to discern); the password you enter is the key. In sum, then, the strength of security today lies in the password; whereas in the past, it lay in the program itself.
Modern Uses of Cryptography
Today, the so-called Data Encryption Standard is the standard encryption method employed by businesses and governments. High-powered applications use much more secure methods; the DES method employs a 56-bit key, which means that in order to crack any password via brute force, you need to go through 2^56 keys, or try about ten-to-the-nineteenth power of permutations. In reality, you would probably have to try a large number of these, instead of the whole thing before stumbling on the correct password. Corporations and governments have much more robust methods of breaking passwords using DES and can accomplish it relatively easily.
More recently, the Advanced Encryption Method (AES), the International Data encryption Algorithm (IDEA), and Blowfish are being advanced to standard use. The password keys associated with these are far harder to break using a brute-force method and are comprised of up to 448-bit keys. It would take over a week of using powerful computers working in parallel to break keys of this magnitude using a trial-and-error method. As more and more information moves to cloud servers and core business precepts of companies also migrate to the cloud, the field of cryptography is expected to grow more robust alongside them to fill the growing need for security.