Sign documents with encrypted QR-code text

GroupDocs.Signature provides ability to secure QR-code signature text 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 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 required algorithm and secure pair key/salt
Create objects of QrCodeSignOptions class and setup property DataEncryption with object of SymmetricEncryption
Call Sign method of Signature class instance and pass QrCodeSignOptions to it.

This example shows how to sign document with secure QR-code signature text.

using (Signature signature = new Signature("sample.pdf"))
{
    // setup key and passphrase
    string key = "1234567890";
    string salt = "1234567890";
    // create data encryption
    IDataEncryption encryption = new SymmetricEncryption(SymmetricAlgorithmType.Rijndael, key, salt);
    // setup QR-Code options
    QrCodeSignOptions options = new QrCodeSignOptions()
    {
        //setup text to be secured
        Text = "This is private text to be secured.",
        EncodeType = QrCodeTypes.QR,
        // specify text encryption
        DataEncryption = encryption,
        // locate and aligh signature
        Height = 100,
        Width = 100,
        VerticalAlignment = VerticalAlignment.Bottom,
        HorizontalAlignment = HorizontalAlignment.Right,
        Margin = new Padding() {  Right = 10, Bottom = 10}
    };
    // sign document to file
    signature.Sign("QRCodeEncryptedText.pdf", options);
}

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.

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