Introduction to cryptography

 Data at Motion Cryptography is required when communicating over any non trusted medium. This medium can be internet, mobile phones, bank automatic teller machines, wireless intercom systems, Bluetooth devices, wireless microphones and portable storage disks. These days, organizations invest heavily to secure all the business communications like emails using cryptographic techniques and products. This is to ensure that no one else other than the trusted recipient can read the message.  Data at Rest Cryptography is must in securely storing all the sensitive and vital data. This is a basic provision mentioned in most of the compliances which an organization must meet. A simple example for this is Encrypting File system (EFS) which is a file system introduced in Windows operating system to provide file system level protection.  Data integrity Cryptography not only protects the information, but also verifies the integrity of data. This is necessary to ensure that the transferred data has not been tampered by a hacker. This is done using the data hashing algorithms, discussed later.