Cryptography is the most popular mechanism for protecting digital documents exchanged across the wire between two parties involved in confidential business transactions.
The basic concept of cryptography is illustrated as follows:
A sender application uses high-speed mathematical algorithms to transform a given piece of data to a complicated combination of digits and numbers just before transmission. The algorithms employed are so complex that it is impossible to reproduce the original data from this resulting chunk.
This meaningless chunk of data is then transmitted across the wire. If any unintended recipients can intercept the communications, they will be able to read only this chunk (from which nothing can be derived), not the original data.
On the receiving end, premeditated reverse transforms are applied in order to decipher the data chunk. The sender has to ensure that only the indented recipients are empowered with reverse transforms.
The transformation process applied at the sender's end is known as encryption; the process at the receiver's end is known as decryption.
Over the years, several famous algorithms that can achieve very high levels of security have evolved. Many of these algorithms use specific combinations of numbers and digitscalled keysduring the encryption/decryption process. Information encrypted by using specific keys can be decrypted only by using corresponding key pairs. This enables the reuse of same encryption algorithms across different applications.