**The Microsoft Base Cryptographic Provider 2.0**
is a general-purpose provider that supports digital signatures and
data encryption. This provider is currently included with the operating
system (either Windows NT®, 2000, or Windows® 95/98).
It is also provided with Microsoft Internet Explorer, Version 3.0 or later.
When AspEncrypt is used with the Microsoft Base Cryptographic Provider,
the following algorithms are available:

Purpose | Name | Key or Hash Size |

Hash | MD2 | 128 bit |

Hash | MD4 | 128 bit |

Hash | MD5 | 128 bit |

Hash | SHA | 160 bit |

Symmetric Encryption | RC2 | 40 bit |

Symmetric Encryption | RC4 | 40 bit |

Public-Key Encryption | RSA | 384 - 512 bit |

Public-Key Signature | RSA | 384 - 16,384 bit 512 bit by default |

**The Microsoft Enhanced Cryptographic Provider**
supports the same capabilities as the Microsoft Base
Cryptographic Provider, but provides for stronger security through longer keys and
additional algorithms.
The Enhanced provider is installed on your machine when you apply the Internet Explorer
128-bit security patch available form http://www.microsoft.com/windows/ie/download/128bit/intro.htm.

When AspEncrypt is used with the Microsoft Enhanced Cryptographic Provider,
the following algorithms are available:

Purpose | Name | Key or Hash Size |

Hash | MD2 | 128 bit |

Hash | MD4 | 128 bit |

Hash | MD5 | 128 bit |

Hash | SHA | 160 bit |

Symmetric Encryption | RC2 | 128 bit |

Symmetric Encryption | RC4 | 128 bit |

Symmetric Encryption | DES | 56 bit |

Symmetric Encryption | Triple DES (2 Keys) | 112 bit |

Symmetric Encryption | Triple DES (3 Keys) | 168 bit |

Public-Key Encryption | RSA | 1,024 bit |

Public-Key Signature | RSA | 384 - 16,384 bit 1,024 bit by default |

**The Microsoft Enhanced RSA and AES Cryptographic Provider (Prototype)** (Windows XP)
and **Microsoft Enhanced RSA and AES Cryptographic Provider** (Windows 2003) provide
support for the Advanced Encryption Standard cipher (also known as *Rijndael*).
The following key lengths are available:

Purpose | Name | Key Size |

Symmetric Encryption | AES | 128 bit |

Symmetric Encryption | AES | 192 bit |

Symmetric Encryption | AES | 256 bit |

AES is not supported on Windows NT or 2000. AES is supported on Windows XP and 2003
by the AspEncrypt versions 2.3 and higher.

**Microsoft Enhanced RSA and AES Cryptographic Provider** on Windows 2003 supports
the long (greater than 160 bit) SHA hash functions:

Purpose | Name | Key Size |

Hash | SHA-256 | 256 bit |

Hash | SHA-384 | 384 bit |

Hash | SHA-512 | 512 bit |