What is cryptography What techniques are used for cryptography-00652
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Cryptography is the technique of converting a message into unintelligible or non-understandable form such that even if some unauthorized or unwanted person intercepts the message he/she would still not be able to make any sense out of it. Cryptography is thousands of years old.
Techniques used for cryptography Substitution In substitution we replace each letter in the message with another to make the message non-understandable. For example, each letter "a" in the message can be replaced with letter "d" and letter "b" with letter "e" and so on. Transposition It is based on scrambling the characters in a message. A transposition system may first write a message into a table row by row then the message can be read and rewritten column by column to make it scrambled.
