Rfc2898DeriveBytes Constructor (String, Int32, Int32)


Initializes a new instance of the Rfc2898DeriveBytes class using a password, a salt size, and number of iterations to derive the key.

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

public Rfc2898DeriveBytes(
	string password,
	int saltSize,
	int iterations


Type: System.String

The password used to derive the key.

Type: System.Int32

The size of the random salt that you want the class to generate.

Type: System.Int32

The number of iterations for the operation.

Exception Condition

The specified salt size is smaller than 8 bytes or the iteration count is less than 1.


The password or salt is null.


iterations is out of range. This parameter requires a non-negative number.

The salt size must be 8 bytes or larger and the iteration count must be greater than zero. The minimum recommended number of iterations is 1000.

RFC 2898 includes methods for creating a key and initialization vector (IV) from a password and salt. You can use PBKDF2, a password-based key derivation function, to derive keys using a pseudo-random function that allows keys of virtually unlimited length to be generated. The Rfc2898DeriveBytes class can be used to produce a derived key from a base key and other parameters. In a password-based key derivation function, the base key is a password and the other parameters are a salt value and an iteration count.

For more information on PBKDF2, see RFC 2898,"PKCS #5: Password-Based Cryptography Specification Version 2.0," available on the Request for Comments Web site. See section 5.2, "PBKDF2," for complete details.

System_CAPS_security Security Note

Never hard-code a password within your source code. Hard-coded passwords can be retrieved from an assembly by using the Ildasm.exe (IL Disassembler), by using a hexadecimal editor, or by simply opening up the assembly in a text editor such as Notepad.exe.

.NET Framework
Available since 2.0
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