Search for encrypted object in QR-code signatures

GroupDocs.Signature provides ability to search for embedded data objects in QR-code signatures (QrCodeSignature) 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 embedded objects in QR-code with standard encryption with GroupDocs.Signature:

Definition of class that was embedded into into QR-Code signature

public class DocumentSignatureData
    public string ID { get; set; }
    public string Author { get; set; }
    [Format("SDate", "yyyy-MM-dd")]
    public DateTime Signed { get; set; }
    [Format("SDFact", "N2")]
    public decimal DataFactor { get; set; }
    public string Comments { get; set; }

Searching for embedded object in QR-code signature

This example shows how to search for embedded object in QR-code signatures.

using (Signature signature = new Signature("QRCodeEncryptedObject.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,
        PageNumber = 1,
        PagesSetup = new PagesSetup() { FirstPage = true, LastPage = true, OddPages = false, EvenPages = false },
        // 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}.", qrCodeSignature.PageNumber,qrCodeSignature.EncodeType);
        DocumentSignatureData documentSignatureData = qrCodeSignature.GetData<DocumentSignatureData>();
        if(documentSignatureData != null)
            Console.WriteLine("QRCode signature has DocumentSignatureData object:\n ID = {0}, Author = {1}, Signed = {2}, DataFactor {3}",
                documentSignatureData.ID, documentSignatureData.Author, documentSignatureData.Signed.ToShortDateString(), documentSignatureData.DataFactor);

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.