Data encryption is a process in which plaintext data is converted into ciphertext so that it cannot be read. More generally known as “encryption,” this process can be accomplished in a wide variety of ways, and with varying degrees of success. Some of the best data encryption can last for centuries, while other types of decryption can be broken in minutes or even seconds by people who are skilled at such tasks. In the digital age, people rely heavily on data encryption on a daily basis. Chances are high that you have received or sent encrypted data at some point today, even if you did not directly perform the encryption or decryption of the data.
In this process, a perfectly ordinary piece of plaintext which can be read by anyone is converted so that it can only be read by someone with a key. One of the simplest forms of data encryption is a simple alphabetic substitution, in which the letters of the alphabet are scrambled to create a key. One could decide, for example, to shift the letters of the alphabet by five places so that “E” stands for “A,” “F” for “B” and so forth for a simple key, or the letters could be assigned at random to make a piece of text more difficult to decipher without the key.
An alphabetic substitution is usually fairly easy to break; in fact, many major newspapers have a simple substitution on their puzzles page for people to solve. More complex methods of data encryption can be used to make a code more challenging to break. With complex codes, people can try to use brute force to crack the encryption, and they may eventually succeed, but it will take a long time. Many methods of encryption focus on keeping the key secure, and allowing the encrypted data to be freely seen, under the argument that once encrypted, the data is harmless, as long as people cannot obtain the key.
There are a number of reasons to need to encrypt data, most of which rely on shielding data from the eyes of other people. Banks, for example, send encrypted data about their clients back and forth, while governments rely on encryption to get secure messages to overseas embassies. Most email programs offer data encryption while sending and receiving so that emails cannot be read by third parties, as do sites which handle personal information like addresses and credit card numbers.
Some encryption protocols are standardized so that people can easily communicate with each other, while in other cases, a key may be developed specifically for use by particular people, and the key is not standardized to make it harder to crack. Personalized keys were once the only way to encrypt data, until shared key encryption allowed people to exchange information about a key across an open network without disclosing the contents of the key itself.