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7a04d2ad86
Made 2 changes to optimize the match results: 1. use a loop to find the next digit of wordbank element and compare with outStr's digit 2. this part need to be optimize with the calculation of the number of occurance of word's probabilities
28 lines
1.4 KiB
JavaScript
28 lines
1.4 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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var wordInOutStr = ""; // temporary store the word inside the outStr, it is used for comparison
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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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// use a loop to find the next digit of wordbank element and compare with outStr's digit
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for ( var j=0; j < wordbank[i].length; j++){
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wordInOutStr += outStr[i+j];
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}
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// this part need to be optimize with the calculation of the number of occurance of word's probabilities
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if (wordbank[i] == wordInOutStr){
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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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