Cryptography
is the practice and study of hiding information. It is also called the code,
but this is not really a good name. It is a science that is used to keep the
information confidential and secure. Modern cryptography is a mix of
mathematics, computer science and electrical engineering. Cryptography is used
in ATM (banking) cards, computer passwords, and shopping on the internet.
If
a message is sent is changed with cryptography (or encrypted) before it is
sent. The method of changing the text is a "code" or, rather, as a “cipher”.
The amended text is "tagged”. The amendment makes the message difficult to
read. Someone who wants to read it should change back (or decrypt). How to
change back it's a secret. Both the individual sending the message and the one
who receives must change the secret way to know, but others may not. Studying
the cypher text called to discover the secret “cryptanalysis” or “cracking"
or sometimes “code breaking”.
Different
types of cryptography can be easier or harder to use and can be better or worse
hide the secret message. Figures use a "key" that is a secret hiding
secret messages. The cryptographic method does no secret. Different people may
have the same method, but using different keys so that they cannot read each others messages. Since Caesar cipher that so many keys as the number of
letters in the alphabet easily cracked by trying all the keys. Figures billions
of keys can be cracked by more complex methods.
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