Encrypt and Decrypt Excel files

Using Microsoft Excel

To set file encryption settings in Microsoft Excel (here Microsoft Excel 2003):

  1. From the Tools menu, select Options. A dialog will appear.
  2. Select the Security tab.
  3. Input a password and click Advanced
  4. Choose the encryption type and confirm the password.

Encrypting Excel file with Aspose.Cells

The following example shows how to encrypt and password protect an excel file using the Aspose.Cells API.

// For complete examples and data files, please go to https://github.com/aspose-cells/Aspose.Cells-for-.NET
// The path to the documents directory.
string dataDir = RunExamples.GetDataDir(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);
// Instantiate a Workbook object.
// Open an excel file.
Workbook workbook = new Workbook(dataDir + "Book1.xls");
// Specify XOR encryption type.
workbook.SetEncryptionOptions(EncryptionType.XOR, 40);
// Specify Strong Encryption type (RC4,Microsoft Strong Cryptographic Provider).
workbook.SetEncryptionOptions(EncryptionType.StrongCryptographicProvider, 128);
// Password protect the file.
workbook.Settings.Password = "1234";
// Save the excel file.
workbook.Save(dataDir + "encryptedBook1.out.xls");

Specifying Password to modify Option

The following example shows how to set the Password to modify Microsoft Excel option for an existing file using the Aspose.Cells API.

// For complete examples and data files, please go to https://github.com/aspose-cells/Aspose.Cells-for-.NET
// The path to the documents directory.
string dataDir = RunExamples.GetDataDir(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);
// Instantiate a Workbook object.
// Open an excel file.
Workbook workbook = new Workbook(dataDir + "Book1.xls");
// Set the password for modification.
workbook.Settings.WriteProtection.Password = "1234";
// Save the excel file.
workbook.Save(dataDir + "SpecifyPasswordToModifyOption.out.xls");

Decrypting Excel file with Aspose.Cells

It is very to open password-protect excel file and decrypt using the Aspose.Cells API as following codes:

//Open encrypted file with password.
LoadOptions loadOptions = new LoadOptions();
loadOptions.Password = "password";
Workbook workbook = new Workbook("Book1.xlsx", loadOptions);
//Remove password.
workbook.Settings.Password = null;
//Save the file.
workbook.Save("Book1.xlsx");

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