The word Crypt in English comes from Latin ‘Crypta’ or Greek ‘Crypte’ means concealed or private.
The entire Information Right Management (IRM) promise rests on being able to encrypt information and then decrypt it for consumption as permitted. If information were not encrypted for instance, anybody would be able to use the information for whatever purpose, whenever from wherever.
Of course, Encryption is not all of IRM, but encryption is an important aspect of IRM. So what is this thing called Encryption. Let us try to answer that one. This not intended for those who know little bit about Encryption; more for those who haven’t even bothered to Google for Encryption.
Encyrption converts piece of information – called plain text – to make in unreadable unless permitted, by means of an algorithm – called cipher - by converting the plain text into information - ciphertext. Of course, the ciphertext, can be reconverted to plain text by means of another key and this is called decryption.
A very simple example of encryption could be adding a letter in alphabet. For instance ‘apple’ can be encrypted to ‘bqqmf’. Of course, cracking such simple algorithm is easy. Hence you require complex algorithms to create military grade encryption.
Some of standard methods of encryption are asymmetric encryption and symmetric encryption. In asymmetric encryption, a different key is used to encrypt and another key is used to decrypt. While as in symmetric encryption the same key is used to encrypt and decrypt. In asymmetric encryption a private key is used to encrypt information and a public key is used to decrypt information.
The advantage with symmetric encryption is that you can decrypt a huge amount of information, in less amount of time. To make things more secure, often the key used for symmetric encryption is encrypted again with asymmetric encryption.
Of course, encryption is a challenge to people who would try unauthorized decryption. The easiest way, though perhaps laborious, even for a computer to attempt unauthorized decryption is method of brute force.
The method to ward of such unsolicited attempt is to use an appropriate key. For instance, information encrypted with 32 bit key can be decrypted in days, but information encrypted with 128 bit key could take years to decrypt.
Hash is another special method of encryption, in which the encrypted information is not intended to be decrypted back. For instance passwords can be encrypted and stored in encrypted format. So when password has to be authenticated, the entered password is encrypted again and tested against stored encrypted password.
Hopefully this introduction has decrypted science of encryption, to some extent.