3 Questions About Certificate

As we know ,certificate is a digitallly-signed security object that bind the public key to the principal who holds the private key.




Say i create a certificate by using create certificate DDL, then use it to encrypt data and decrypt data as follows:





Code Block
create certificate cert1 encryption by password='p@ssw0rd1' with subject='certificate test'
go
declare @plaintext varchar(100)
set @plaintext='abcd'
declare @cipher varbinary(8000)
set @cipher=encryptbycert(cert_id('cert1'),@plaintext)
select convert(varchar,decryptbycert(cert_id('cert1'),@cipher,N'p@ssw0rd1'))












Is that mean i create public key implicitly when i run "create certificate cert1 encryption by password='p@ssw0rd1' with subject='certificate test'"?

What cryptography algorithm would be use when i use the certificate to encrypt data ?
Where is private key? I ensure I use the public key which generated from "create certificate " DDL to encrypt data .I want to know which private key i used when i execute decryptbycert to decrypt.