Reading QRcodes in Salesforce1

Get the Static Resource File QRCode From the below url
https://github.com/LazarSoft/jsqrcode

Visual force page:
<apex:page >
    <script type="text/javascript"
      src="//ajax.aspnetcdn.com/ajax/jQuery/jquery-1.10.2.min.js"></script>
 
<script type="text/javascript" src="{!URLFOR($Resource.QRCode, 'jsqrcode-master/src/grid.js')}"></script>
<script type="text/javascript" src="{!URLFOR($Resource.QRCode, 'jsqrcode-master/src/version.js')}"></script>
<script type="text/javascript" src="{!URLFOR($Resource.QRCode, 'jsqrcode-master/src/detector.js')}"></script>
<script type="text/javascript" src="{!URLFOR($Resource.QRCode, 'jsqrcode-master/src/formatinf.js')}"></script>
<script type="text/javascript" src="{!URLFOR($Resource.QRCode, 'jsqrcode-master/src/errorlevel.js')}"></script>
<script type="text/javascript" src="{!URLFOR($Resource.QRCode, 'jsqrcode-master/src/bitmat.js')}"></script>
<script type="text/javascript" src="{!URLFOR($Resource.QRCode, 'jsqrcode-master/src/datablock.js')}"></script>
<script type="text/javascript" src="{!URLFOR($Resource.QRCode, 'jsqrcode-master/src/bmparser.js')}"></script>
<script type="text/javascript" src="{!URLFOR($Resource.QRCode, 'jsqrcode-master/src/datamask.js')}"></script>
<script type="text/javascript" src="{!URLFOR($Resource.QRCode, 'jsqrcode-master/src/rsdecoder.js')}"></script>
<script type="text/javascript" src="{!URLFOR($Resource.QRCode, 'jsqrcode-master/src/gf256poly.js')}"></script>
<script type="text/javascript" src="{!URLFOR($Resource.QRCode, 'jsqrcode-master/src/gf256.js')}"></script>
<script type="text/javascript" src="{!URLFOR($Resource.QRCode, 'jsqrcode-master/src/decoder.js')}"></script>
<script type="text/javascript" src="{!URLFOR($Resource.QRCode, 'jsqrcode-master/src/qrcode.js')}"></script>
<script type="text/javascript" src="{!URLFOR($Resource.QRCode, 'jsqrcode-master/src/findpat.js')}"></script>
<script type="text/javascript" src="{!URLFOR($Resource.QRCode, 'jsqrcode-master/src/alignpat.js')}"></script>
<script type="text/javascript" src="{!URLFOR($Resource.QRCode, 'jsqrcode-master/src/databr.js')}"></script>

  <form>
      <div style="float:right;">
    <input type="file" onchange="previewFile()" /><br/>
    </div>
  <h1>Preview</h1>
   <div style="height:200px">
    <img src="" id="preview" height="200" alt="Image preview..." />
   </div>
  </form>

    <p>If the image above looks clear, click the decode button.  If not, try again!</p>
    <button id="decode" onclick="decode()">Decode</button>
  <script>

  function read(a)
  {
        alert(a);
        if( (typeof sforce != 'undefined') && (sforce != null) ) {
            sforce.one.navigateToSObject(a);
        }
        else {
            window.location="/" + a;
        }      
  }      
     
  $(document).ready(function() {
        qrcode.callback = read;
  });


function previewFile() {
  var preview = document.querySelector('#preview');
  var file    = document.querySelector('input[type=file]').files[0];
  var reader  = new FileReader();

  reader.onloadend = function () {
    preview.src = reader.result;
  }

  if (file) {
    reader.readAsDataURL(file);
  } else {
    preview.src = "";
  }
}

function decode() {
    try
    {
    var preview=document.querySelector('#preview');
    qrcode.decode(preview.src);
    }
    catch (e)
    {
       alert('Error - ' + e);
    }
}

</script>
</apex:page>


Check the Available for Salesforce mobile apps checkbox

Create a visualforce tab for this visualforce page

click Setup-> Mobile Adminstration -> Mobile navigation -> Move the Tab to the right

Login to salesforce1 you can see the tab and click on the chose file. That will prompt you to take snap
and when the scan completes click on decode.

Encrypting and decrypting String

Blob data = Blob.valueOf('Test data to encrypted');
Blob cryptoValue = Crypto.generateAesKey(256);
Blob encryptedData = Crypto.encryptWithManagedIV('AES256', cryptoValue, data);
Blob decryptedData = Crypto.decryptWithManagedIV('AES256', cryptoValue, encryptedData);
String decryptedDataString = decryptedData.toString();
System.debug(decryptedDataString);

How do you convert a Blob to string?

Blob b;
String b64;
String strUrlUTF8;
String strOriginal;

strOriginal = 'Joe’s Café & Bar ♫';
System.debug('String strOriginal: [' + strOriginal + ']');

strUrlUTF8 = EncodingUtil.urlEncode(strOriginal, 'UTF-8');
System.debug('String strUrlUTF8: [' + strUrlUTF8 + ']');

b = Blob.valueOf(strUrlUTF8);
System.debug('Blob b: [' + b.toString() + ']');

b64 = EncodingUtil.base64Encode(b);
System.debug('String b64: [' + b64 + ']');

b = EncodingUtil.base64Decode(b64);
System.debug('Blob b: [' + b.toString() + ']');

strUrlUTF8 = b.toString();
System.debug('String strUrlUTF8: [' + strUrlUTF8 + ']');

strOriginal = EncodingUtil.urlDecode(strUrlUTF8, 'UTF-8');
System.debug('String strOriginal: [' + strOriginal + ']');