EncryptedKey Class


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Represents the <EncryptedKey> element in XML encryption. This class cannot be inherited.

Namespace:   System.Security.Cryptography.Xml
Assembly:  System.Security (in System.Security.dll)


[HostProtectionAttribute(SecurityAction.LinkDemand, MayLeakOnAbort = true)]
public sealed class EncryptedKey : EncryptedType


Initializes a new instance of the EncryptedKey class.


Gets or sets the optional <CarriedKeyName> element in XML encryption.


Gets or sets the CipherData value for an instance of an EncryptedType class.(Inherited from EncryptedType.)


Gets or sets the Encoding attribute of an EncryptedType instance in XML encryption.(Inherited from EncryptedType.)


Gets or sets the <EncryptionMethod> element for XML encryption.(Inherited from EncryptedType.)


Gets or sets the <EncryptionProperties> element in XML encryption.(Inherited from EncryptedType.)


Gets or sets the Id attribute of an EncryptedType instance in XML encryption.(Inherited from EncryptedType.)


Gets of sets the <KeyInfo> element in XML encryption.(Inherited from EncryptedType.)


Gets or sets the MimeType attribute of an EncryptedType instance in XML encryption.(Inherited from EncryptedType.)


Gets or sets the optional Recipient attribute in XML encryption.


Gets or sets the <ReferenceList> element in XML encryption.


Gets or sets the Type attribute of an EncryptedType instance in XML encryption.(Inherited from EncryptedType.)


Adds an <EncryptionProperty> child element to the <EncryptedProperties> element in the current EncryptedType object in XML encryption.(Inherited from EncryptedType.)


Adds a <DataReference> element to the <ReferenceList> element.


Adds a <KeyReference> element to the <ReferenceList> element.


Determines whether the specified object is equal to the current object.(Inherited from Object.)


Serves as the default hash function. (Inherited from Object.)


Gets the Type of the current instance.(Inherited from Object.)


Returns the XML representation of the EncryptedKey object.(Overrides EncryptedType.GetXml().)


Loads the specified XML information into the <EncryptedKey> element in XML encryption.(Overrides EncryptedType.LoadXml(XmlElement).)


Returns a string that represents the current object.(Inherited from Object.)

This class represents the <EncryptedKey> element in XML encryption. The <EncryptedKey> element is used to send encryption keys. It can be created in a stand-alone XML document, be placed within an application document, or be inside an <EncryptedData> element as a child of a <KeyInfo> element. The key value is always encrypted to the recipient. When <EncryptedKey> is decrypted, the resulting key is made available to the <EncryptionMethod> algorithm without any additional processing.

The <EncryptedKey> element is similar to the <EncryptedData> element of the EncryptedData class except that the data encrypted is always a key value.

The following example illustrates how to encrypt and decrypt an XML element by using the EncryptedKey class. This example then displays the values of various properties of the EncryptedKey class to the console.

using System;
using System.Xml;
using System.Security.Cryptography;
using System.Security.Cryptography.Xml;

class Program
	static void Main(string[] args)

		// Create an XmlDocument object.
		XmlDocument xmlDoc = new XmlDocument();

		// Load an XML file into the XmlDocument object.
			xmlDoc.PreserveWhitespace = true;
		catch (Exception e)

		// Create a new RSA key.  This key will encrypt a symmetric key,
		// which will then be imbedded in the XML document.  
		RSA rsaKey = new RSACryptoServiceProvider();

			// Encrypt the "creditcard" element.
			Encrypt(xmlDoc, "creditcard", rsaKey, "rsaKey");

			// Inspect the EncryptedKey element.

			// Decrypt the "creditcard" element.
			Decrypt(xmlDoc, rsaKey, "rsaKey");

		catch (Exception e)
			// Clear the RSA key.


	public static void Encrypt(XmlDocument Doc, string ElementToEncrypt, RSA Alg, string KeyName)
		// Check the arguments.  
		if (Doc == null)
			throw new ArgumentNullException("Doc");
		if (ElementToEncrypt == null)
			throw new ArgumentNullException("ElementToEncrypt");
		if (Alg == null)
			throw new ArgumentNullException("Alg");

		// Find the specified element in the XmlDocument
		// object and create a new XmlElemnt object.

		XmlElement elementToEncrypt = Doc.GetElementsByTagName(ElementToEncrypt)[0] as XmlElement;

		// Throw an XmlException if the element was not found.
		if (elementToEncrypt == null)
			throw new XmlException("The specified element was not found");


		// Create a new instance of the EncryptedXml class 
		// and use it to encrypt the XmlElement with the 
		// a new random symmetric key.

		// Create a 256 bit Rijndael key.
		RijndaelManaged sessionKey = new RijndaelManaged();
		sessionKey.KeySize = 256;

		EncryptedXml eXml = new EncryptedXml();

		byte[] encryptedElement = eXml.EncryptData(elementToEncrypt, sessionKey, false);

		// Construct an EncryptedData object and populate
		// it with the desired encryption information.

		EncryptedData edElement = new EncryptedData();
		edElement.Type = EncryptedXml.XmlEncElementUrl;

		// Create an EncryptionMethod element so that the 
		// receiver knows which algorithm to use for decryption.

		edElement.EncryptionMethod = new EncryptionMethod(EncryptedXml.XmlEncAES256Url);

		// Encrypt the session key and add it to an EncryptedKey element.
		EncryptedKey ek = new EncryptedKey();

		byte[] encryptedKey = EncryptedXml.EncryptKey(sessionKey.Key, Alg, false);

		ek.CipherData = new CipherData(encryptedKey);

		ek.EncryptionMethod = new EncryptionMethod(EncryptedXml.XmlEncRSA15Url);

		// Set the KeyInfo element to specify the
		// name of the RSA key.

		// Create a new KeyInfo element.
		edElement.KeyInfo = new KeyInfo();

		// Create a new KeyInfoName element.
		KeyInfoName kin = new KeyInfoName();

		// Specify a name for the key.
		kin.Value = KeyName;

		// Add the KeyInfoName element to the 
		// EncryptedKey object.

		// Add the encrypted key to the 
		// EncryptedData object.

		edElement.KeyInfo.AddClause(new KeyInfoEncryptedKey(ek));

		// Add the encrypted element data to the 
		// EncryptedData object.
		edElement.CipherData.CipherValue = encryptedElement;

		// Replace the element from the original XmlDocument
		// object with the EncryptedData element.

		EncryptedXml.ReplaceElement(elementToEncrypt, edElement, false);


	public static void Decrypt(XmlDocument Doc, RSA Alg, string KeyName)
		// Check the arguments.  
		if (Doc == null)
			throw new ArgumentNullException("Doc");
		if (Alg == null)
			throw new ArgumentNullException("Alg");
		if (KeyName == null)
			throw new ArgumentNullException("KeyName");

		// Create a new EncryptedXml object.
		EncryptedXml exml = new EncryptedXml(Doc);

		// Add a key-name mapping.
		// This method can only decrypt documents
		// that present the specified key name.
		exml.AddKeyNameMapping(KeyName, Alg);

		// Decrypt the element.


	static void InspectElement(XmlDocument Doc)
		// Get the EncryptedKey element from the XMLDocument object.
		XmlElement encryptedKey = Doc.GetElementsByTagName("EncryptedKey")[0] as XmlElement;

		// Create a new EncryptedKey object.
		EncryptedKey k = new EncryptedKey();

		// Load the XML from the document to
		// initialize the EncryptedKey object.

		// Display the properties.
		// Most values are Null by default.
		Console.WriteLine("EncryptedKey.KeyInfo: " + k.KeyInfo.GetXml().InnerXml);
		Console.WriteLine("EncryptedKey.Id: " + k.Id);
		Console.WriteLine("EncryptedKey.CarriedKeyName: " + k.CarriedKeyName);
		Console.WriteLine("EncryptedKey.CipherData: " + k.CipherData.GetXml().InnerXml);
		Console.WriteLine("EncryptedKey.Encoding: " + k.Encoding);
		Console.WriteLine("EncryptedKey.EncryptionMethod: " + k.EncryptionMethod.GetXml().InnerXml);
		if (k.EncryptionProperties.Count >= 1)
			Console.WriteLine("EncryptedKey.EncryptionProperties: " + k.EncryptionProperties[0].GetXml().InnerXml);
		Console.WriteLine("EncryptedKey.MimeType: " + k.MimeType);
		Console.WriteLine("EncryptedKey.Recipient: " + k.Recipient);

		if (k.ReferenceList.Count >= 1)
			Console.WriteLine("EncryptedKey.ReferenceList: " + k.ReferenceList[0].GetXml().InnerXml);


.NET Framework
Available since 2.0

Any public static ( Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

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