advances in encryption

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Encryption
Encryption
Encryption is the transformation of data into a form unreadable by anyone without a secret decryption key. It is to ensure privacy by keeping the information hidden from anyone for whom it is not intended, even those who can see the encrypted data. one may wish to encrypt files on a hard disk to prevent an intruder from reading them.
In a multi-user setting, encryption allows secure communication over an insecure channel. Sender wishes to send a message to receiver so that no one else besides receiver can read it. Sender encrypts the message, which is called the plaintext, with an encryption key; the encrypted message, called the ciphertext, is sent to receiver. Receiver decrypts the ciphertext with the decryption key and reads the message. An attacker may either try to obtain the secret key or to recover th e plaintext without using the secret key. In a secure cryptosystem, the plaintext cannot be recovered from the ciphertext except by using the decryption key. In a symmetric cryptosystem, a single key serves as both the encryption and decryption keys.
Authentication and digital signature
Authentication in a digital setting is a process whereby the receiver of a digital message can be confident of the identity of the sender and/or the integrity of the message. Authentication protocols can be based on either conventional secret-key cryptosystems ...