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.

The hash size for the SHA1 algorithm is 160 bits.

The following example computes the SHA1 hash for data and stores it in result. This example assumes that there is a predefined constant DATA_SIZE.

Dim data(DATA_SIZE) As Byte
Dim result() As Byte
       
Dim sha As New SHA1CryptoServiceProvider()
' This is one implementation of the abstract class SHA1.
result = sha.ComputeHash(data)

byte[] data = new byte[DATA_SIZE];
byte[] result; 
 
SHA1 sha = new SHA1CryptoServiceProvider(); 
// This is one implementation of the abstract class SHA1.
result = sha.ComputeHash(data);

array<Byte>^ data = gcnew array<Byte>( DATA_SIZE );
array<Byte>^ result;

SHA1^ sha = gcnew SHA1CryptoServiceProvider;
// This is one implementation of the abstract class SHA1.
result = sha->ComputeHash( data );

ubyte data[] = new ubyte[data_Size];
ubyte result[];
SHA1 sha = new SHA1CryptoServiceProvider();

// This is one implementation of the abstract class SHA1.
result = sha.ComputeHash(data);

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

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

.NET Framework

.NET Compact Framework