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SymmetricAlgorithm.CreateEncryptor Method

Creates a symmetric encryptor object with the current Key property and initialization vector (IV).

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

'Declaration
Public Overridable Function CreateEncryptor As ICryptoTransform

Return Value

Type: System.Security.Cryptography.ICryptoTransform
A symmetric encryptor object.

If the current Key property is Nothing, the GenerateKey method is called to create a new random Key. If the current IV property is Nothing, the GenerateIV method is called to create a new random IV.

Use the CreateDecryptor overload with the same signature to decrypt the result of this method.

The following example encrypts a string using the transform object returned from the CreateEncryptor method.

Imports System
Imports System.Security.Cryptography
Imports System.Text

Class EncryptorExample
     Private Shared quote As String = _
         "Things may come to those who wait, but only the " + _
         "things left by those who hustle. -- Abraham Lincoln" 

     Public Shared Sub Main()
         Dim aesCSP As New AesCryptoServiceProvider()

         aesCSP.GenerateKey()
         aesCSP.GenerateIV()
         Dim encQuote() As Byte = EncryptString(aesCSP, quote)

         Console.WriteLine("Encrypted Quote:" + vbNewLine)
         Console.WriteLine(Convert.ToBase64String(encQuote))

         Console.WriteLine(vbNewLine + "Decrypted Quote:" + vbNewLine)
         Console.WriteLine(DecryptBytes(aesCSP, encQuote))
     End Sub 

     Public Shared Function EncryptString(symAlg As SymmetricAlgorithm, inString As String) As Byte()
         Dim inBlock() As Byte = UnicodeEncoding.Unicode.GetBytes(inString)
         Dim xfrm As ICryptoTransform = symAlg.CreateEncryptor()
         Dim outBlock() As Byte = xfrm.TransformFinalBlock(inBlock, 0, inBlock.Length)

         Return outBlock
     End Function 

     Public Shared Function DecryptBytes(symAlg As SymmetricAlgorithm, inBytes() As Byte) As String 
         Dim xfrm As ICryptoTransform = symAlg.CreateDecryptor()
         Dim outBlock() As Byte = xfrm.TransformFinalBlock(inBytes, 0, inBytes.Length)

         return UnicodeEncoding.Unicode.GetString(outBlock)
     End Function 
End Class

.NET Framework

Supported in: 4.6, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Supported in: Windows Phone 8.1

Supported in: Windows Phone Silverlight 8.1

Supported in: Windows Phone Silverlight 8

Windows Phone 8.1, Windows Phone 8, Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

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

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