A.3. Key Size Limits and Internet Explorer

Microsoft uses certain cryptographic providers which support only a subset of potential key sizes for RSA and for ECC keys. These are listed in Table A.2, “Providers and Key Sizes”.
The key size support can impact the configuration of profiles that will be used with Internet Explorer and, possibly, the configuration of the CA.

Table A.2. Providers and Key Sizes

Algorithm Provider Supported Key Sizes
ECC Microsoft Software Key Storage Provider
  • nistp256
  • nistp384
  • nistp521
ECC Microsoft Smart Card Key Storage Provider
  • nistp256
  • nistp384
  • nistp521
RSA Microsoft Base Cryptographic Provider
  • 1024
RSA Microsoft Strong Cryptographic Provider
  • 1024
  • 2048
  • 3072
  • 4096
  • 8192
RSA Enhanced Cryptographic Provider
  • 1024
  • 2048
  • 3072
  • 4096
  • 8192
RSA Microsoft Software Key Storage Provider
  • 1024
  • 2048
  • 3072
  • 4096
  • 8192