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AsymmetricAlgorithm Class

Represents the abstract base class from which all implementations of asymmetric algorithms must inherit.

For a list of all members of this type, see AsymmetricAlgorithm Members.


[Visual Basic]
MustInherit Public Class AsymmetricAlgorithm
   Implements IDisposable
public abstract class AsymmetricAlgorithm : IDisposable
public __gc __abstract class AsymmetricAlgorithm : public
public abstract class AsymmetricAlgorithm implements IDisposable

Thread Safety

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


Asymmetric cryptographic algorithms, also known as public-key algorithms, require that both sender and receiver maintain a pair of related keys: a private key and a public key. Both keys are unique to the entity. The public key can be made available to anyone; this key is used for encoding data that is sent to a receiver. The private key must be kept private by the receiver; this key is used for decoding messages encoded using the receiver's public key. RSACryptoServiceProvider is an implementation of a public-key algorithm.

You can also use public-key systems to form digital signatures. Digital signatures are used to help authenticate the identity of another entity and to help protect the integrity of data. For example, to use a public-key system to digitally sign a message, the sender first applies a hash function to the message to create a message digest. The sender then encrypts the message digest with the sender's private key to create the sender's personal signature, because this private key uniquely identifies the sender. Upon receiving the message and signature, the receiver decrypts the signature using the sender's public key to recover the message digest and hashes the message using the same hash algorithm that the sender used. If the message digest that the receiver computes exactly matches the message digest received from the sender, then the receiver can assume that the message came from the sender. Note that anyone can verify a signature, because the sender's public key is common knowledge. This method does not retain the secrecy of the message; for the message to be secret, it must also be encrypted as described previously. The receiver decrypts the message using the receiver's private key and then computes the message digest as before. DSACryptoServiceProvider is an implementation of a digital signature algorithm. You can also use RSACryptoServiceProvider to create and verify a digital signature.

The present implementation provides concrete classes for RSA and DSA only. This class cannot be extended by application code.


Namespace: System.Security.Cryptography

Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family

Assembly: Mscorlib (in Mscorlib.dll)

See Also

AsymmetricAlgorithm Members | System.Security.Cryptography Namespace | Cryptographic Services