HashAlgorithm Class
Represents the base class from which all implementations of cryptographic hash algorithms must derive.
Assembly: mscorlib (in mscorlib.dll)
Hash functions are fundamental to modern cryptography. These functions map binary strings of an arbitrary length to small binary strings of a fixed length, known as hash values. A cryptographic hash function has the property that it is computationally infeasible to find two distinct inputs that hash to the same value. Hash functions are commonly used with digital signatures and for data integrity.
The hash is used as a unique value of fixed size representing a large amount of data. Hashes of two sets of data should match if the corresponding data also matches. Small changes to the data result in large unpredictable changes in the hash.
Notes to Inheritors:When you inherit from the HashAlgorithm class, you must override the following members: HashCore and HashFinal.
The following code example computes the SHA1CryptoServiceProvider hash for an array. This example assumes that there is a predefined byte array dataArray[]. SHA1CryptoServiceProvider is a derived class of HashAlgorithm.
System.Security.Cryptography.HashAlgorithm
System.Security.Cryptography.KeyedHashAlgorithm
System.Security.Cryptography.MD5
System.Security.Cryptography.RIPEMD160
System.Security.Cryptography.SHA1
System.Security.Cryptography.SHA256
System.Security.Cryptography.SHA384
System.Security.Cryptography.SHA512
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.