<PackageReference Include="System.Security.Cryptography.Cng" Version="5.0.0-preview.4.20251.6" />

System.Security.Cryptography.CngExportPolicies

public enum CngExportPolicies
Specifies the key export policies for a key.
namespace System.Security.Cryptography { public enum CngExportPolicies { None = 0, AllowExport = 1, AllowPlaintextExport = 2, AllowArchiving = 4, AllowPlaintextArchiving = 8 } }