Data Encryption

Related Terms: Biometrics; Internet Security

Data encryption refers to the process of transforming electronic information into a scrambled form that can only be read by someone who knows how to translate the code. Encryption was already used by Julius Caesar in the days of the Roman Empire to scramble letters and messages. It played a major role in many wars and in military circles generally. Encryption has turned electronic in modern times. It is today very important in the business world as well. It is the easiest and most practical method of protecting data stored, processed, or transmitted electronically. It makes electronic commerce possible by protecting credit card and personal information. It is also commonly used to scramble the contents of contracts, sensitive documents, and personal messages sent over the Internet. More and more institutions, including small businesses with data to protect, also use encryption to protect data on their computer in-house.

BASICS

Encryption comes from the science of cryptography, which involves the coding and decoding of messages in order to protect their contents. One of the most ancient forms of it is letter substitution—thus, for instance, sending the next letter in the alphabet instead of the actual letter in the text. Ifmmp xpsme/ thus spells out Hello world. In the electronic environment, every symbol has a numerical value expressible in binary notation. Thus the letter A is 01000001 and the letter a is 01100001. Humans cannot make out a vast stream of zeroes and ones, but it is child's play for a computer. Patterns of letters are therefore transformed before transmission by using an arbitrary key; the key may be used in arithmetic, logical, or other ways to make the underlying meaning inaccessible to anyone who does not know the key. The more binary digit the key has, the more difficult the code is to crack—meaning that the longer it takes a computer system, attempting to break the code, to find the key by trial and error. Very safe encryption methods in the mid-2000s made use of 128-bit keys; such keys were used in financial transactions; but newer systems were being fielded using 168 and 256 bits.

TYPES OF ENCRYPTION PROGRAMS

Single Key

There are two main types of data encryption systems. In the first—which is variously known as private key, single key, secret key, or symmetric encryption—the sender and the recipient of the data both hold the same key for translation. This single key is used both to code and to decode information exchanged between two parties. Since the same key is used to encrypt and decrypt messages, the parties involved must exchange the key secretly and keep it secure from outsiders. Private key encryption systems are usually faster than other types; they can be cumbersome when more than two parties need to exchange information.

Public Key

The second, and more commonly used, type of data encryption system is known as a public key system. This approach involves two separate keys: a public key for encoding information; and a private key for decoding information. The public key can be held and used by any number of individuals and businesses, whereas only one party holds the private key. The system is particularly useful in electronic commerce: the merchant holds the private key and all customers have access to the public key. The public key can be posted on a Web page or stored in an easily accessible key repository. Public key encryption systems are widely available on the Internet and heavily used by large companies.

The best-known data encryption program is called RSA. It was developed in the late 1970s by three graduates of the Massachusetts Institute of Technology'—Ronald Rivest, Adi Shamir, and Leonard Adleman. As of the mid-2000, there were more than a billion installations of RSA encryption programs on computer systems worldwide. RSA scrambles data based on the product of two prime numbers, each of which is 100 digits long. RSA is known as a public key encryption system, meaning that many people can use it to encode information, but only the person who holds the key (or knows the value of the two prime numbers) can decode it again. RSA is embedded in hundreds of popular software products, including Windows, Netscape Navigator, Quicken, and Lotus Notes. It is also available as a free download from the World Wide Web.

A number of other data encryption programs enjoy wide use as well. Examples include Pretty Good Privacy (PGP), which is considered easy to use; Secure Sockets Layer (SSL), which is used by many companies that accept online credit card orders; Secure Electronic Transactions (SET), another popular method of handling credit card purchases that is backed by Visa, Mastercard, Microsoft, IBM, and other major players in electronic commerce; and Data Encryption Standard (DES), which was invented by IBM in the mid-1970s and became the U.S. government standard.

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