<PackageReference Include="System.Security.Cryptography.Pkcs" Version="10.0.12" />

System.Security.Cryptography.Pkcs.SubjectIdentifierOrKey

public sealed class SubjectIdentifierOrKey
The SubjectIdentifierOrKey class defines the type of the identifier of a subject, such as a CmsSigner or a CmsRecipient. The subject can be identified by the certificate issuer and serial number, the hash of the subject key, or the subject key.
public SubjectIdentifierOrKeyType Type { get; }

The Type property retrieves the type of subject identifier or key. The subject can be identified by the certificate issuer and serial number, the hash of the subject key, or the subject key.

public object Value { get; }

The Value property retrieves the value of the subject identifier or key. Use the Type property to determine the type of subject identifier or key, and use the Value property to retrieve the corresponding value.