What is the cipher?

American English term ciphers and especially the British English variant, Cypher , are used freely to refer to any coded or encrypted message, and especially for referring to messages encrypted using a secret key. The word came to English through old French and medieval Latin, but comes from an Arabic word that is rewritten in English as sifr , a variant of a word that means "to be empty" and refers to zero that comes from the same Arabic root. In the field of cryptography - Shaled Writing, there may be cipher that means "encrypt text" or a noun that refers to either a particular cryptographic system or to the turn -key used in this system or to the text transmitted by this system. In other words, the ciphers are three different things.

When Cipher's nouns are used to indicate a message that was encrypted, refers to what is more specifically called ciphertext . It stands unlike the freeA text that refers to a common untreated material. Plaintext is what a person has before encryption and after decryption, with Ciphertext temporarily replacing the simple text when it is protected.

In the event that the noun cipher is used to refer to the secret key, it refers to a value that is or can be used to encrypt a simple message. The symmetrical key is used to encrypt and decrypt the dial. If asymmetric keys are used, there is a data encryption key and a separate key to decrypting data.

This brings us to the meaning of cipher , in which it is referred to the encryption and decryption system. The system that uses a symmetrical key is called private key encryption. The system that uses asymmetric keys is called the public key encryption. Other categorization of cipher systems include transposition ciphers and substitutions of Ciphers that describe different sonsa common treatment of simple text. The famous cipher used by Julius Caesar and often mentioned, was a simple substitution cipher. The ciphers are also categorized as block ciphers or streaming ciphers.

ciphers are used to facilitate private communication of many types. Ciphers can be used by government, spy, company or terrorist. For example, ciphers are used on the Internet for transactions for e -maily and credit cards. In addition to the production of messages unreadable by those for which they were not intended, ciphers also help in verifying messages and ensure the recipient that the message comes from the sender from which it should be from.