Encryption is a method which allows information to be hidden so that it cannot be read without special knowledge or tools. Once this is done the information is encrypted. Decryption is a way to change an encrypted piece of information back into unencrypted form. This is called the decrypted form.
A simple kind of encryption for words is ROT13. In ROT13, letters of the alphabet are changed with each other using a simple pattern. For example, A changes to N, B changes to O, C changes to P, and so on. Each letter is "rotated" by 13 spaces. Using the ROT13 cipher, the words Simple English Wikipedia becomes Fvzcyr Ratyvfu Jvxvcrqvn. The ROT13 cipher is very easy to decrypt. Because there are 26 letters in the English alphabet, if a letter is rotated two times by 13 letters each time, the original letter will be obtained. So applying the ROT13 cipher a second time brings back the original text.
Most kinds of encryption are more complex. Some are made only for text. Others are made for binary computer files like pictures and music. Today, the encryption system used the most is RSA. Any computer file can be encrypted with RSA.
On the Internet and PayPal [change]
Encryption is used on the Internet. Web sites use encryption to protect private information. On the Internet, several encryption protocols are used, such as Secure Sockets Layer (SSL), IPsec, and SSH. They use the RSA encryption system and others. The protocol for protected web browsing is called HTTPS. Mostly URL encryption contain MD5 Algorithm. Various alogorithm are available on the internet/market depending upon the need.