Implementation of Algorithms for Identity Based Encryption and Decryption

Background

The public key encryption is a cryptographic system that uses two keys, a public key known to everyone and a private or secret key known only to the recipient of the message. When a user Alice wants to send a secure message to user Bob, she uses Bob's public key to encrypt the message, Bob then uses his private key to decrypt it. An important element to the public key system is that the public and private keys are related in such a way that only the public key can be used to encrypt messages and only the corresponding private key can be used to decrypt them. Moreover, it is virtually impossible to deduce the private key if you know the public key. Users will exchange public keys; this transaction does not need to be done in a secure manner because the release of public keys does not threaten the security of any private information. After this swap, someone who wishes to send private information to another user will encrypt the data with the intended recipient’s public key and then pass along the encrypted message. The recipient, who will keep his or her private key secure under any circumstance, can use the private key to decrypt the encoded message.