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A one-to-one function and its inverse can be used to make information secure. The function is used to encrypt a message, and its inverse is used to decrypt the encrypted message. The following numerical values are assigned to each letter of the alphabet: A C D m G H K L M 12 13 4 5 16 17 18 19 10 11 12 13 N O P O R S U V W Y Z 14 115 16 |17 18 19 20 21 22 23 24 25 26 Using the function f(x)=3x-1, the message "HELLO" would be encrypted 23 14 35 35 44 since H corresponds to 8 and f(8) =3(8)-1=23, etc