what is cryptography?

Answer 1

Cryptography (or cryptology; derived from Greek κρυπτός kryptós "hidden," and the verb γράφω gráfo "write") is the study of message secrecy. In modern times, it has become a branch of information theory, as the mathematical study of information and especially its transmission from place to place. The noted cryptographer Ron Rivest has observed that "cryptography is about communication in the presence of adversaries." It is a central contributor to several fields: information security and related issues, particularly, authentication, and access control. One of cryptography's primary purposes is hiding the meaning of messages, not usually the existence of such messages. Cryptography also contributes to computer science, central to the techniques used in computer and network security for such things as access control and information confidentiality. Cryptography is also used in many applications encountered in everyday life; the security of ATM cards, computer passwords, and electronic commerce all depend on cryptography.

There are two kinds of cryptosystems: symmetric and asymmetric. Symmetric cryptosystems use the same key (the secret key) to encrypt and decrypt a message, and asymmetric cryptosystems use one key (the public key) to encrypt a message and a different key (the private key) to decrypt it. Assymetric cryptosystems are also called public key cryptosystems.

Symmetric cryptosystems have a problem: how do you transport the secret key from the sender to the recipient securely and in a tamperproof fashion? If you could send the secret key securely, then, in theory, you wouldn't need the symmetric cryptosystem in the first place -- because you would simply use that secure channel to send your message. Frequently, trusted couriers are used as a solution to this problem. Another, more efficient and reliable solution is a public key cryptosystem, such as RSA, which is used in the popular security tool PGP.

Answer 2

Cryptography is a method of storing and transmitting data in a particular form so that only those for whom it is intended can read and process it.

Cryptography is closely related to the disciplines of cryptology and cryptanalysis. Cryptography includes techniques such as microdots, merging words with images, and other ways to hide information in storage or transit. However, in today's computer-centric world, cryptography is most often associated with scrambling plaintext (ordinary text, sometimes referred to as cleartext) into ciphertext (a process called encryption), then back again (known as decryption). Individuals who practice this field are known as cryptographers.

Answer 3

Cryptography is the way by which we are able to secretely send our messages. The message we have is often called ´plain text´. We make some modifications/changes to our plain text. This may be rearranging the message, assigning some number to each letter of the message, applying some mathematical tricks.This modified message is called ´cipher text´, which is the message that is sent.

At the receiving side, the person knows how to get back the original message. Sometimes a magic number called ´key´ is involved which when applied to the cipher text gives back ur plain text i.e., the original message

Answer 4

Codes and decoding. It's a fascinating subject now that it's all done with computers. The algorithms needed to code a message, and then to decode someone else's coded message, are really complex compared to what they were in the days when a code book was the standard equipment.

It's not just spies and that sort of secret, either; your credit card information is encrypted in the computer. Many things are encrypted by computers for confidentiality, and sometimes those codes are broken by "hackers."

Answer 5

Cryptography is the science of secret writing. Its name comes from the Greek words Kryptos, meaning hidden, and graphene, which means writing.

Answer 6

Cryptography (or cryptology; derived from Greek κρυπτός kryptós "hidden," and the verb γράφω gráfo "write") is the study of message secrecy.

Answer 7

simply Cryptography is Encription and Decription of plane text in to Cypher Text

Answer 8

Public key encryption refers to one of those cypher or code structure huge-spread as public key cryptography that makes use of two keys, or a key pair), to encrypt and decrypt archives. between both keys is a public key, which all and sundry can use to encrypt a message for the owner of that key. The encrypted message is allotted and the recipient makes use of his or her deepest key to decrypt it. it is the inspiration of public and private key encryption.

Answer 9

the system used in a code.

Answer 10

coding