Simple encryption

[Raknarg]

For anyone interested in how encryption works, this is one simple method I discovered recently. This is a program that I made to encrypt strings with a key code, and can basically only be unlocked with that key. Without it, the message is a jumbled mess.

Turing:

const dictionary := "ABCDEFGHIJKLMNOPQRSTUVWXYZ" const numbers := "1234567890" fcn encrypt (str, key : string) : string     var news := ""     var s := Str.Upper (str)     for i : 1 .. length (s)         if index (dictionary, s (i)) > 0 then             news += chr (65 + (((ord (s (i)) - 65) + (ord (key (i mod length (key) + 1)) - 65)) mod 26))         elsif index (numbers, s (i)) > 0 then             news += chr (49 + (((ord (s (i)) - 49) + (ord (key (i mod length (key) + 1)) - 49)) mod 10))         else             news += s (i)         end if     end for     result news end encrypt fcn decrypt (str, key : string) : string     var news := ""     var s := Str.Upper (str)     for i : 1 .. length (s)         if index (dictionary, s (i)) > 0 then             news += chr (65 + (((ord (s (i)) - 65) - (ord (key (i mod length (key) + 1)) - 65)) mod 26))         elsif index (numbers, s (i)) > 0 then             news += chr (49 + (((ord (s (i)) - 49) - (ord (key (i mod length (key) + 1)) - 49)) mod 10))         else             news += s (i)         end if     end for     result news end decrypt var input, message : string put "Input message to encrypt: " .. get message : * put "Input your password: " .. get input : * message := encrypt (message, input) cls loop     put "Your encrypted message: ", message     put "Input the password to display the message: " ..     get input     put "The message with this key reads: ", decrypt (message, input)     put "Press any key to continue..."     loop         exit when hasch     end loop     cls end loop

Basically, it takes the string you input, then adds the value of your key in the same position to that letter. if you don't know what ord and chr do, ord takes in a letter and returns its ASCII value. chr takes an ASCII value and returns the corresponding letter.

[mirhagk]

ahh the good ol vigenere cipher, just make sure your password is as long as the message and random

[Raknarg]

yup. Cool to note that the password "dogdog" is the same as the password "dog". I'm not sure how you'd get around that.

[mirhagk]

You'd have to get into more complicated password generators.