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X509AsymmetricSecurityKey.EncryptKey Method

Encrypts the specified encrypted key using the specified cryptographic algorithm.

Namespace:  System.IdentityModel.Tokens
Assembly:  System.IdentityModel (in System.IdentityModel.dll)

public override byte[] EncryptKey(
	string algorithm,
	byte[] keyData


Type: System.String
The cryptographic algorithm to encrypt the key.
Type: System.Byte[]
An array of Byte that contains the key to encrypt.

Return Value

Type: System.Byte[]
An array of Byte that contains the encrypted key.


The X.509 certificate specified in the constructor has a public key that was not generated using the RSA algorithm.


The algorithm parameter is not supported. The supported algorithms are XmlEncRSA15Url and XmlEncRSAOAEPUrl.

Use the XmlEncRSA15Url or XmlEncRSAOAEPUrl fields to specify the algorithm.

.NET Framework

Supported in: 4, 3.5, 3.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.