key size
The size in bits of the public key. Generally, the larger the key size, the more resistant the private key is to cryptanalysis (subversion of the cryptosystem).

You should choose the largest key size possible. Larger keys are harder to break and provide a more secure environment for your application, but take longer to process.

The following table will help you determine the restrictions on key size depending on your intended use:

Using Export-Grade NICI:

Key Size Key Usage Type
2048 Bits Digital Signature Signature, Custom
1024 Bits Key Encipherment Digital Signature Encryption, Signature, Custom, SSL or TLS
768 Bits Key Encipherment Digital Signature Encryption, Signature, Custom, SSL or TLS
512 Bits Key Encipherment Digital Signature Data Encipherment Unspecified, Encryption, Signature, Custom, SSL or TLS

Using U.S. and Canadian Version of NICI (no restrictions):

Key Size Key Usage Type
2048, 1024, 768, 512 Bits Key Encipherment Digital Signature Data Encipherment Unspecified, Encryption, Signature, Custom, SSL or TLS