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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)

public virtual ICryptoTransform CreateEncryptor()

Return Value

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

If the current Key property is null, the GenerateKey method is called to create a new random Key. If the current IV property is null, 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.

using System;
using System.Security.Cryptography;
using System.Text;

class EncryptorExample
     private static string quote =
         "Things may come to those who wait, but only the " +
         "things left by those who hustle. -- Abraham Lincoln";

     public static void Main()
         AesCryptoServiceProvider aesCSP = new AesCryptoServiceProvider();

         byte[] encQuote = EncryptString(aesCSP, quote);

         Console.WriteLine("Encrypted Quote:\n");

         Console.WriteLine("\nDecrypted Quote:\n");
         Console.WriteLine(DecryptBytes(aesCSP, encQuote));

     public static byte[] EncryptString(SymmetricAlgorithm symAlg, string inString)
         byte[] inBlock = UnicodeEncoding.Unicode.GetBytes(inString);
         ICryptoTransform xfrm = symAlg.CreateEncryptor();
         byte[] outBlock = xfrm.TransformFinalBlock(inBlock, 0, inBlock.Length);

         return outBlock;

     public static string DecryptBytes(SymmetricAlgorithm symAlg, byte[] inBytes)
         ICryptoTransform xfrm = symAlg.CreateDecryptor();
         byte[] outBlock = xfrm.TransformFinalBlock(inBytes, 0, inBytes.Length);

         return UnicodeEncoding.Unicode.GetString(outBlock);

.NET Framework

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

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, 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.