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22 lines
1.1 KiB
JavaScript
22 lines
1.1 KiB
JavaScript
/******************************************************
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Find and retrieve the encryption key automatically
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Note: This is a draft version, please help to modify, Thanks!
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******************************************************/
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function keyFinder(str){ // str is used to get the input of encrypted string
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var key = 0; // return zero means the key can not be found
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var wordbank =["is","Is","am","Am","are","Are","have","Have","has","Has","may","May","be","Be"];
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//var shiftNum = 0; //count the number of key shifted
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var inStr = str.toString(); //convert the input to String
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var outStr = ""; // store the output value
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//document.getElementById("debug").innerHTML = shiftNum; // debug: display the shifted number(s)
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for (var i=0; i<(52); i++){ //try the number of key shifted, the sum of character from a-z and A-Z is 26*2=52
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outStr = caesarCipherEncodeAndDecodeEngine(inStr,i); // use the encrytpion engine to decrypt the input string, shiftNum=i
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for ( var i=0; i<wordbank.length; i++){
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if (wordbank[i] == outStr[i]+outStr[i+1]{
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key=i;
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}
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}
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}
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return key;
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}
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