Search for encrypted text in QR-code signatures

GroupDocs.Signature provides ability to search over secure QR-code signature with standard or custom encryption. Standard encryption is implemented over class SymmetricEncryption class. Creation of this object expects 3 arguments like encryption algorithm enumeration **SymmetricAlgorithmType **with one of following values (DES, TripleDES, RC2, Rijndael), string value key and string value salt.

Here are the steps to search for secure QR-code text with standard encryption with GroupDocs.Signature:

  • Create new instance of Signature class and pass source document path or stream as a constructor parameter.

  • Compose object of SymmetricEncryption class with same parameters as secured QR-code was signed with.

  • Create objects of QrCodeSearchOptions class and setup property QrCodeSearchOptions.DataEncryption with object of SymmetricEncryption 

  • Call Search method of Signature class instance and pass QrCodeSearchOptions to it.

This example shows how to search for secure QR-code signature text.

using (Signature signature = new Signature("QRCodeEncryptedText.pdf"))
    // setup key and pasphrase
    string key = "1234567890";
    string salt = "1234567890";
    // create data encryption
    IDataEncryption encryption = new SymmetricEncryption(SymmetricAlgorithmType.Rijndael, key, salt);
    QrCodeSearchOptions options = new QrCodeSearchOptions()
        // specify special pages to search on 
        AllPages = true,
        // specify special QRCode type to search
        EncodeType = QrCodeTypes.QR,
        DataEncryption = encryption
    // search for signatures in document
    List<QrCodeSignature> signatures = signature.Search<QrCodeSignature>(options);
    Console.WriteLine("\nSource document contains following signatures.");
    foreach (var qrCodeSignature in signatures)
        Console.WriteLine("QRCode signature found at page {0} with type {1} and text '{2}'", qrCodeSignature.PageNumber,
            qrCodeSignature.EncodeType.TypeName, qrCodeSignature.Text);

More resources

GitHub Examples

You may easily run the code above and see the feature in action in our GitHub examples:

Free Online App 

Along with full-featured .NET library we provide simple, but powerful free Apps.
You are welcome to eSign PDF, Word, Excel, PowerPoint documents with free to use online GroupDocs Signature App.