The System.Security.Cryptography namespace provides cryptographic services, including secure encoding and decoding of data, as well as many other operations, such as hashing, random number generation, and message authentication. For more information, see Cryptographic Services.

	Class	Description
	AsnEncodedData	Represents Abstract Syntax Notation One (ASN.1)-encoded data.
	AsnEncodedDataCollection	Represents a collection of AsnEncodedData objects. This class cannot be inherited.
	AsnEncodedDataEnumerator	Provides the ability to navigate through an AsnEncodedDataCollection object. This class cannot be inherited.
	AsymmetricAlgorithm	Represents the abstract base class from which all implementations of asymmetric algorithms must inherit.
	AsymmetricKeyExchangeDeformatter	Represents the base class from which all asymmetric key exchange deformatters derive.
	AsymmetricKeyExchangeFormatter	Represents the base class from which all asymmetric key exchange formatters derive.
	AsymmetricSignatureDeformatter	Represents the abstract base class from which all implementations of asymmetric signature deformatters derive.
	AsymmetricSignatureFormatter	Represents the base class from which all implementations of asymmetric signature formatters derive.
	CryptoAPITransform	Performs a cryptographic transformation of data. This class cannot be inherited.
	CryptoConfig	Accesses the cryptography configuration information.
	CryptographicAttributeObject	Contains a type and a collection of values associated with that type.
	CryptographicAttributeObjectCollection	Contains a set of CryptographicAttributeObject objects.
	CryptographicAttributeObjectEnumerator	Provides enumeration functionality for the CryptographicAttributeObjectCollection collection. This class cannot be inherited.
	CryptographicException	The exception that is thrown when an error occurs during a cryptographic operation.
	CryptographicUnexpectedOperationException	The exception that is thrown when an unexpected operation occurs during a cryptographic operation.
	CryptoStream	Defines a stream that links data streams to cryptographic transformations.
	CspKeyContainerInfo	Provides additional information about a cryptographic key pair. This class cannot be inherited.
	CspParameters	Contains parameters that are passed to the cryptographic service provider (CSP) that performs cryptographic computations. This class cannot be inherited.
	DeriveBytes	Represents the abstract base class from which all classes that derive byte sequences of a specified length inherit.
	DES	Represents the base class for the Data Encryption Standard (DES) algorithm from which all DES implementations must derive.
	DESCryptoServiceProvider	Defines a wrapper object to access the cryptographic service provider (CSP) version of the Data Encryption Standard (DES) algorithm. This class cannot be inherited.
	DSA	Represents the abstract base class from which all implementations of the Digital Signature Algorithm (DSA) must inherit.
	DSACryptoServiceProvider	Defines a wrapper object to access the cryptographic service provider (CSP) implementation of the DSA algorithm. This class cannot be inherited.
	DSASignatureDeformatter	Verifies a Digital Signature Algorithm (DSA) PKCS#1 v1.5 signature.
	DSASignatureFormatter	Creates a Digital Signature Algorithm (DSA) signature.
	FromBase64Transform	Converts a CryptoStream from base 64.
	HashAlgorithm	Represents the base class from which all implementations of cryptographic hash algorithms must derive.
	HMAC	Represents the abstract class from which all implementations of Hash-based Message Authentication Code (HMAC) must derive.
	HMACMD5	Computes a Hash-based Message Authentication Code (HMAC) using the MD5 hash function.
	HMACRIPEMD160	Computes a Hash-based Message Authentication Code (HMAC) using the RIPEMD160 hash function.
	HMACSHA1	Computes a Hash-based Message Authentication Code (HMAC) using the SHA1 hash function.
	HMACSHA256	Computes a Hash-based Message Authentication Code (HMAC) using the SHA256 hash function.
	HMACSHA384	Computes a Hash-based Message Authentication Code (HMAC) using the SHA384 hash function.
	HMACSHA512	Computes a Hash-based Message Authentication Code (HMAC) using the SHA512 hash function.
	KeyedHashAlgorithm	Represents the abstract class from which all implementations of keyed hash algorithms must derive.
	KeySizes	Determines the set of valid key sizes for the symmetric cryptographic algorithms.
	MACTripleDES	Computes a Message Authentication Code (MAC) using TripleDES for the input data CryptoStream.
	MaskGenerationMethod	Represents the abstract class from which all mask generator algorithms must derive.
	MD5	Represents the abstract class from which all implementations of the MD5 hash algorithm inherit.
	MD5CryptoServiceProvider	Computes the MD5 hash value for the input data using the implementation provided by the cryptographic service provider (CSP). This class cannot be inherited.
	Oid	Represents a cryptographic object identifier. This class cannot be inherited.
	OidCollection	Represents a collection of Oid objects. This class cannot be inherited.
	OidEnumerator	Provides the ability to navigate through an OidCollection object. This class cannot be inherited.
	PasswordDeriveBytes	Derives a key from a password using an extension of the PBKDF1 algorithm.
	PKCS1MaskGenerationMethod	Computes masks according to PKCS #1 for use by key exchange algorithms.
	ProtectedData	Provides methods for protecting and unprotecting data. This class cannot be inherited.
	ProtectedMemory	Provides methods for protecting and unprotecting memory. This class cannot be inherited.
	RandomNumberGenerator	Represents the abstract class from which all implementations of cryptographic random number generators derive.
	RC2	Represents the base class from which all implementations of the RC2 algorithm must derive.
	RC2CryptoServiceProvider	Defines a wrapper object to access the cryptographic service provider (CSP) implementation of the RC2 algorithm. This class cannot be inherited.
	Rfc2898DeriveBytes	Implements password-based key derivation functionality, PBKDF2, by using a pseudo-random number generator based on HMACSHA1.
	Rijndael	Represents the base class from which all implementations of the Rijndael symmetric encryption algorithm must inherit.
	RijndaelManaged	Accesses the managed version of the Rijndael algorithm. This class cannot be inherited.
	RijndaelManagedTransform	Performs a cryptographic transformation of data using the Rijndael algorithm. This class cannot be inherited.
	RIPEMD160	Represents the abstract class from which all implementations of the MD160 hash algorithm inherit.
	RIPEMD160Managed	Computes the RIPEMD160 hash for the input data using the managed library.
	RNGCryptoServiceProvider	Implements a cryptographic Random Number Generator (RNG) using the implementation provided by the cryptographic service provider (CSP). This class cannot be inherited.
	RSA	Represents the base class from which all implementations of the RSA algorithm inherit.
	RSACryptoServiceProvider	Performs asymmetric encryption and decryption using the implementation of the RSA algorithm provided by the cryptographic service provider (CSP). This class cannot be inherited.
	RSAOAEPKeyExchangeDeformatter	Decrypts Optimal Asymmetric Encryption Padding (OAEP) key exchange data.
	RSAOAEPKeyExchangeFormatter	Creates Optimal Asymmetric Encryption Padding (OAEP) key exchange data using RSA.
	RSAPKCS1KeyExchangeDeformatter	Decrypts the PKCS #1 key exchange data.
	RSAPKCS1KeyExchangeFormatter	Creates the PKCS#1 key exchange data using RSA.
	RSAPKCS1SignatureDeformatter	Verifies an RSA PKCS #1 version 1.5 signature.
	RSAPKCS1SignatureFormatter	Creates an RSA PKCS #1 version 1.5 signature.
	SafeHandle
	SHA1	Computes the SHA1 hash for the input data.
	SHA1CryptoServiceProvider	Computes the SHA1 hash value for the input data using the implementation provided by the cryptographic service provider (CSP). This class cannot be inherited.
	SHA1Managed	Computes the SHA1 hash for the input data using the managed library.
	SHA256	Computes the SHA256 hash for the input data.
	SHA256Managed	Computes the SHA256 hash for the input data using the managed library.
	SHA384	Computes the SHA384 hash for the input data.
	SHA384Managed	Computes the SHA384 hash for the input data using the managed library.
	SHA512	Computes the SHA512 hash for the input data.
	SHA512Managed	Computes the SHA512 hash algorithm for the input data using the managed library.
	SignatureDescription	Contains information about the properties of a digital signature.
	SymmetricAlgorithm	Represents the abstract base class from which all implementations of symmetric algorithms must inherit.
	ToBase64Transform	Converts a CryptoStream to base 64.
	TripleDES	Represents the base class for Triple Data Encryption Standard algorithms from which all TripleDES implementations must derive.
	TripleDESCryptoServiceProvider	Defines a wrapper object to access the cryptographic service provider (CSP) version of the TripleDES algorithm. This class cannot be inherited.

Interfaces

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	Interface	Description
	ICryptoTransform	Defines the basic operations of cryptographic transformations.
	ICspAsymmetricAlgorithm	Defines methods that allow an AsymmetricAlgorithm class to enumerate key container information, and import and export Microsoft Cryptographic API (CAPI)–compatible key blobs.

Structures

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	Structure	Description
	DSAParameters	Contains the typical parameters for the DSA algorithm.
	RSAParameters	Represents the standard parameters for the RSA algorithm.

Enumerations

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	Enumeration	Description
	CipherMode	Specifies the block cipher mode to use for encryption.
	CryptoStreamMode	Specifies the mode of a cryptographic stream.
	CspProviderFlags	Specifies flags that modify the behavior of the cryptographic service providers (CSP).
	DataProtectionScope	Specifies the scope of the data protection to be applied by the Protect method.
	FromBase64TransformMode	Specifies whether white space should be ignored in the base 64 transformation.
	KeyNumber	Specifies whether to create an asymmetric signature key or an asymmetric exchange key.
	MemoryProtectionScope	Specifies the scope of memory protection to be applied by the Protect method.
	PaddingMode	Specifies the type of padding to apply when the message data block is shorter than the full number of bytes needed for a cryptographic operation.