Key Length Comparison

  • Article

When it is used, the Microsoft Enhanced Cryptographic Provider provides an application with stronger security than is currently available with the Microsoft RSA Base Cryptographic Provider. This provides users more protection for sensitive data .

The following table shows the minimum, default, and maximum key lengths by algorithm and provider.

Provider Algorithms Minimum key length Default key length Maximum key length
MS Base RC4 and RC2 40 40 56
MS Base DES 56 56 56
MS Enhanced RC4 and RC2 40 128 128
MS Enhanced DES 56 56 56
MS Enhanced 3DES 112 112 112 112
MS Enhanced 3DES 168 168 168
DSS/DH Base RC4 and 40 40 56
DSS/DH Base DES 56 56 56
DSS/DH Enh RC4 and 40 128 128
DSS/DH Enh DES 56 56 56
DSS/DH Enh 3DES 168 168 168

The Enhanced Provider is backward compatible with the Base Provider distributed with CryptoAPI 1.0, with the following exception. For session keys, both cryptographic service providers (CSP) are limited to generating and deriving keys of default key length: 40 bit for the Base Provider, and 128 bit for the Enhanced Provider, which precludes the Enhanced Provider from creating keys with Base Provider–compatible key lengths. However, the Enhanced Provider can import key lengths of any size, up to 128 bits.

Warning   If you use the Microsoft RSA Base Provider to create a certification authority, your license to issue certificates is limited to certificates intended for use in the context of your particular application or service.

See Also

Cryptography | Microsoft Cryptographic System | Microsoft RSA Base Provider | Microsoft Enhanced Cryptographic Provider | Certificates

 Last updated on Thursday, April 08, 2004

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