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DES.IsSemiWeakKey Method

Determines whether the specified key is semi-weak.

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

public static bool IsSemiWeakKey(
	byte[] rgbKey
)

Parameters

rgbKey
Type: System.Byte[]

The secret key to test for semi-weakness.

Return Value

Type: System.Boolean
true if the key is semi-weak; otherwise, false.

ExceptionCondition
CryptographicException

The size of the rgbKey parameter is not valid.

Semi-weak keys are pairs of keys that result in ciphers that are easy to break. If text is encrypted with a semi-weak key, encrypting the resulting cipher with the partner of that semi-weak key returns the original text. There are six known semi-weak key pairs for the Data Encryption Standard (DES) algorithm; this method checks for those semi-weak keys.

Attempting to set a semi-weak key results in a CryptographicException. When GenerateKey is called to create a random key, a semi-weak key will never be returned.

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC

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

.NET Framework

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

.NET Compact Framework

Supported in: 3.5, 2.0
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