SQL Server Self Signed Cert - no private key?

I recently turn on SSL encryption using SQL server self-signed cert then I start to ponder more about 1) encryption algorithm, authentication method It seems that the encryption/hashing algorithm used depends on the SChannel negotiation between the client/server's OS. - fine. 2) key length of the self-signed cert. I tried query this select name, pvt_key_encryption_type_desc from sys.certificates ##MS_SQLResourceSigningCertificate## NO_PRIVATE_KEY ##MS_SQLReplicationSigningCertificate## NO_PRIVATE_KEY ##MS_SQLAuthenticatorCertificate## NO_PRIVATE_KEY ##MS_AgentSigningCertificate## NO_PRIVATE_KEY ##MS_PolicySigningCertificate## NO_PRIVATE_KEY ##MS_SmoExtendedSigningCertificate## NO_PRIVATE_KEY ##MS_SchemaSigningCertificate990F36EF1B3577FE5687C7465F0A5135DE9E6834## NO_PRIVATE_KEY q1) can I check if the cert use for SSL encryption is the MS_SQLAuthenticatorCertifcate ? q2) How could a SSL encryption / CERT work with "NO PRIVATE KEY" ? In all my understanding, a cert/asymmetric encryption will involved a PUBLIC key (provided in the cert) for encryption, and the owner of the cert will have its PRIVATE key for decryption ? Why is this not the case here ?