DES.IsSemiWeakKey Method (Byte[])


Determines whether the specified key is semi-weak.

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

public static bool IsSemiWeakKey(
	byte[] 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.

Exception Condition

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.

.NET Framework
Available since 1.1
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