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RIPEMD160 Class

Updated: February 2009

Represents the abstract class from which all implementations of the MD160 hash algorithm inherit.

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

public ref class RIPEMD160 abstract : public HashAlgorithm

Hash functions map binary strings of an arbitrary length to small binary strings of a fixed length. A cryptographic hash function has the property that it is computationally infeasible to find two distinct inputs that hash to the same value; that is, 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.

RIPEMD-160 is a 160-bit cryptographic hash function. It is intended for use as a replacement for the 128-bit hash functions MD4, MD5, and RIPEMD. RIPEMD was developed in the framework of the EU project RIPE (RACE Integrity Primitives Evaluation, 1988-1992).


Newer hash functions, such as the Secure Hash Algorithms SHA-256 and SHA-512, are available. Consider using the SHA256 class or the SHA512 class instead of the RIPEMD160 class.

The following code example calculates the RIPEMD160 hash for all files in a directory.

using namespace System;
using namespace System::IO;
using namespace System::Security::Cryptography;

// Print the byte array in a readable format. 
void PrintByteArray( array<Byte>^array )
   int i;
   for ( i = 0; i < array->Length; i++ )
      Console::Write( String::Format( "{0:X2}", array[ i ] ) );
      if ( (i % 4) == 3 )
            Console::Write( " " );


int main()
   array<String^>^args = Environment::GetCommandLineArgs();
   if ( args->Length < 2 )
      Console::WriteLine( "Usage: hashdir <directory>" );
      return 0;


      // Create a DirectoryInfo object representing the specified directory.
      DirectoryInfo^ dir = gcnew DirectoryInfo( args[ 1 ] );

      // Get the FileInfo objects for every file in the directory. 
      array<FileInfo^>^files = dir->GetFiles();

      // Initialize a RIPE160 hash object.
      RIPEMD160 ^ myRIPEMD160 = RIPEMD160Managed::Create();

      // Compute and print the hash values for each file in directory.
      System::Collections::IEnumerator^ myEnum = files->GetEnumerator();
      while ( myEnum->MoveNext() )
         FileInfo^ fInfo = safe_cast<FileInfo^>(myEnum->Current);

         // Create a fileStream for the file.
         FileStream^ fileStream = fInfo->Open( FileMode::Open );

         // Compute the hash of the fileStream.
         hashValue = myRIPEMD160->ComputeHash( fileStream );

         // Write the name of the file to the Console.
         Console::Write( "{0}: ", fInfo->Name );

         // Write the hash value to the Console.
         PrintByteArray( hashValue );

         // Close the file.
      return 0;
   catch ( DirectoryNotFoundException^ ) 
      Console::WriteLine( "Error: The directory specified could not be found." );
   catch ( IOException^ ) 
      Console::WriteLine( "Error: A file in the directory could not be accessed." );


Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

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

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




February 2009

Added note about newer hash functions SHA-256 and SHA-512.

Information enhancement.