Unit 7 Listen and Read:
Cryptography
Cryptography involves creating written or generated codes that allow information to be kept secret. Cryptography converts data into a format that is unreadable for an unauthorized user, allowing it to be transmitted without unauthorized entities decoding it back into a readable format, thus compromising the data. Information security uses cryptography on several levels. The information cannot be read without a key to decrypt it. The information maintains its integrity during transit and while being stored. This means that the sender and the delivery of a message can be verified. Cryptography also allows senders and receivers to authenticate each other through the use of key pairs. There are various types of algorithms for encryption. A cryptographic key is a string of bits used by a cryptographic algorithm to transform plain text into cipher text or vice versa. Symmetric encryption requires only one key, which is used to encrypt and decrypt data. Asymmetric encryption uses two different keys: one for encryption and one for decryption.