System.Security.Cryptography.MD5 Class

Represents the abstract class from which all implementations of the System.Security.Cryptography.MD5 hash algorithm inherit.

See Also: MD5 Members


public abstract class MD5 : 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.

The hash size for the System.Security.Cryptography.MD5 algorithm is 128 bits.

The erload:System.Security.Cryptography.HashAlgorithm.ComputeHash methods of the System.Security.Cryptography.MD5 class return the hash as an array of 16 bytes. Note that some MD5 implementations produce a 32-character, hexadecimal-formatted hash. To interoperate with such implementations, format the return value of the erload:System.Security.Cryptography.HashAlgorithm.ComputeHash methods as a hexadecimal value.


Newer hash functions, such as the Secure Hash Algorithms SHA-256 and SHA-512, are available. Consider using the System.Security.Cryptography.SHA256 class or the System.Security.Cryptography.SHA512 class instead of the System.Security.Cryptography.MD5 class. Use System.Security.Cryptography.MD5 only for compatibility with legacy applications and data.


Namespace: System.Security.Cryptography
Assembly: mscorlib (in mscorlib.dll)
Assembly Versions: 1.0.5000.0,,