Everyday there are possibly millions of transactions made that involve the exchange of personal information. Obviously, those that provide that information would like to know that the information they send is safe and secure. On the Internet making information secure is handled by encrypting the data before it is sent, and decrypting it once it reaches its destination.

This post will describe the encryption process and how it is used to keep information safe.

## Definition of Encryption

Encryption is the process of encoding data to ensure that unauthorized parties cannot view it. When data is encrypted, the data is first passed through an algorithm and is converted into cyphertext, which is the encrypted data. To accomplish the encryption, a key or code provided by you is used to encrypt the data, which will make the encryption difficult to crack.

There are two systems used for encryption: Symmetric-key encryption and Public-key encryption (asymmetric). The next section will discuss the two systems.

## Encryption Systems

A symmetric-key encryption system uses a secret key or code to encode the data. When the information is passed to another computer, the code is passed along separately. The second computer then uses the secret code to decode the data. A symmetric-key system is fast but is not as secure as the public-key system. If someone were to intercept the data and the code, then they could easily decode the data.

In a public-key system there are two keys: a public key and a private key. A public key is given out by a secured computer to any computer that wants to establish a secure communication. When the data is to passed from the client’s computer, it is first encoded with the public key and then sent to the secured computer. The secured computer then uses the private key along with the public key to decode the data.

## Number of Public Keys

So how many keys are possible for encryption? It all depends on the bit strength of the encryption. The bit strength of the encryption can vary such as 40-bit or 128-bit. To get the number of keys, simply raise 2 to the power of the bit strength. For example, for 128-bit encryption the number of possible keys is 2^{128} or 340,282,366,920,938,000,000,000,000,000,000,000,000 keys.

Although it may look like determining the correct key is impossible, just remember that computers are getting more powerful, so it is taking less time to determine the key through brute force. This is not to say that your data is not secure, as it still takes a long time to crack 128-bit encryption, at least to the point where it may not be worth while.