Fredrik said:There are lots of things wrong with that. A person who sends encrypted emails isn't going to want you to be able to read them. They're not going to want anyone who has intercepted a message to be able to read it.
It sounds like at least 3 people will have access to it. The third is the website administrator, i.e. you. Actually it sounds like everyone who will be using your encryption software will have access to it. Suppose that many people are using the system, and that A wants to send a message to B that only B can read, even if E intercepts it somehow. How does she do that? By your description, it sounds like E will have access to the decryption tool, even if she has so far only been using the system to send secret messages to F.Jamin2112 said:That's why the idea here is that only the 2 people in correspondence have access to the decrypting tool.
Fredrik said:It sounds like at least 3 people will have access to it. The third is the website administrator, i.e. you. Actually it sounds like everyone who will be using your encryption software will have access to it. Suppose that many people are using the system, and that A wants to send a message to B that only B can read, even if E intercepts it somehow. How does she do that? By your description, it sounds like E will have access to the decryption tool, even if she has so far only been using the system to send secret messages to F.
<html>
<head>
<title>Simple encrypt/decrypt</title>
<style type="text/css">
body
{
background-color: #A9F5F2;
width: 900px;
padding: 0px;
}
.outerdiv
{
margin: 5px;
border: 2px solid #FF8000;
background-color: #FFFFFF;
}
.outerdiv > p
{
margin: 5px;
word-wrap:break-word
}
.outerdiv > h1
{
margin: 5px;
}
#col1
{
width: 500x;
height: 800px;
float: left;
}
#col2
{
width: 295px;
height: 1500px;
float: right;
font-family: Courier New;
overflow: hidden;
}
#title1div
{
font-family: Arial;
width: 100%;
}
#insctdiv
{
font-family: Arial;
width: 100%;
}
#iptdiv
{
height: 400px;
width: 100%;
}
#buttonsdiv
{
text-align: center;
width: 100%;
}
#inputText
{
width: 100%;
height: 100%;
resize: none;
}
</style>
<script type="text/javascript">
function encrypt()
{
var text = document.getElementById("inputText").value;
newstring = "";
/* Make newstring a string of the bit representations of
the ASCII values of its thisCharacters in order.
*/
for (var i = 0, j = text.length; i < j; i++)
{
bits = text.charCodeAt(i).toString(2);
newstring += new Array(8-bits.length+1).join('0') + bits;
}
/* Compress newstring by taking each substring of 3, 4, ..., 9
consecutive 1's or 0's and it by the number of such consecutive
thisCharacters followed by the thisCharacter.
EXAMPLES:
"10101000010111" --> "10101401031"
"001100011111111111111" --> "0011319151"
*/
newstring = newstring.replace(/([01])\1{2,8}/g, function($0, $1) { return ($0.length + $1);});
document.getElementById("inputText").value = newstring;
}
function decrypt()
{
var text = document.getElementById("inputText").value;
text.trim();
text = text.replace(/([2-9])([01])/g, function (all, replacementCount, bit)
{
return Array(+replacementCount + 1).join(bit);
}).split(/(.{8})/g).reduce(function (str, byte)
{
return str + String.fromCharCode(parseInt(byte, 2));
}, "");
document.getElementById("inputText").value = text;
}
function changeMatrixText()
{
var newtext = "";
for (var i = 0; i < 2530; i++)
newtext += Math.floor((Math.random()*10)+1) % 2 ? "0" : "1";
document.getElementById("matrixText").innerHTML = newtext;
}
</script>
</head>
<body>
<div id="col1">
<div class="outerdiv" id="title1div">
<h1>Reversible text encryption algorithm</h1>
</div>
<div class="outerdiv" id="insctdiv">
<p>Type in or paste text below, then click <b>Encrypt</b> or <b>Decrypt</b></p>
</div>
<div class="outerdiv" id="iptdiv">
<textarea id="inputText" scrolling="yes"></textarea>
</div>
<div class="outerdiv" id="buttonsdiv">
<button onclick="encrypt()"><b>Encrypt</b></button>
<button onclick="decrypt()"><b>Decrypt</b></button>
</div>
</div>
<div class="outerdiv" id="col2">
<p id="matrixText"></p>
</div>
<script type="text/javascript">
setInterval(changeMatrixText, 200);
</script>
</body>
</html>Jamin2112 said:I came up with a reversible text encryption scheme and I'm trying to figure out how to make it useful. How do you suggest I do that?
In cryptography, a timing attack is a side channel attack in which the attacker attempts to compromise a cryptosystem by analyzing the time taken to execute cryptographic algorithms. Every logical operation in a computer takes time to execute, and the time can differ based on the input; with precise measurements of the time for each operation, an attacker can work backwards to the input.
Jamin2112 said:Anyways ...
Open this in your browser to try my encoder and decoder.
Code:<html> <head> <title>Simple encrypt/decrypt</title> <style type="text/css"> body { background-color: #A9F5F2; width: 900px; padding: 0px; } .outerdiv { margin: 5px; border: 2px solid #FF8000; background-color: #FFFFFF; } .outerdiv > p { margin: 5px; word-wrap:break-word } .outerdiv > h1 { margin: 5px; } #col1 { width: 500x; height: 800px; float: left; } #col2 { width: 295px; height: 1500px; float: right; font-family: Courier New; overflow: hidden; } #title1div { font-family: Arial; width: 100%; } #insctdiv { font-family: Arial; width: 100%; } #iptdiv { height: 400px; width: 100%; } #buttonsdiv { text-align: center; width: 100%; } #inputText { width: 100%; height: 100%; resize: none; } </style> <script type="text/javascript"> function encrypt() { var text = document.getElementById("inputText").value; newstring = ""; /* Make newstring a string of the bit representations of the ASCII values of its thisCharacters in order. */ for (var i = 0, j = text.length; i < j; i++) { bits = text.charCodeAt(i).toString(2); newstring += new Array(8-bits.length+1).join('0') + bits; } /* Compress newstring by taking each substring of 3, 4, ..., 9 consecutive 1's or 0's and it by the number of such consecutive thisCharacters followed by the thisCharacter. EXAMPLES: "10101000010111" --> "10101401031" "001100011111111111111" --> "0011319151" */ newstring = newstring.replace(/([01])\1{2,8}/g, function($0, $1) { return ($0.length + $1);}); document.getElementById("inputText").value = newstring; } function decrypt() { var text = document.getElementById("inputText").value; text.trim(); text = text.replace(/([2-9])([01])/g, function (all, replacementCount, bit) { return Array(+replacementCount + 1).join(bit); }).split(/(.{8})/g).reduce(function (str, byte) { return str + String.fromCharCode(parseInt(byte, 2)); }, ""); document.getElementById("inputText").value = text; } function changeMatrixText() { var newtext = ""; for (var i = 0; i < 2530; i++) newtext += Math.floor((Math.random()*10)+1) % 2 ? "0" : "1"; document.getElementById("matrixText").innerHTML = newtext; } </script> </head> <body> <div id="col1"> <div class="outerdiv" id="title1div"> <h1>Reversible text encryption algorithm</h1> </div> <div class="outerdiv" id="insctdiv"> <p>Type in or paste text below, then click <b>Encrypt</b> or <b>Decrypt</b></p> </div> <div class="outerdiv" id="iptdiv"> <textarea id="inputText" scrolling="yes"></textarea> </div> <div class="outerdiv" id="buttonsdiv"> <button onclick="encrypt()"><b>Encrypt</b></button> <button onclick="decrypt()"><b>Decrypt</b></button> </div> </div> <div class="outerdiv" id="col2"> <p id="matrixText"></p> </div> <script type="text/javascript"> setInterval(changeMatrixText, 200); </script> </body> </html>