The Secure property returns True if the current
page was retrieved using a secure connection. If the connection was
not encrypted, or there was a problem with the server certificate,
this property will return False. The value of this property
reflects the most recent navigation state. During navigation, this
value may change. For example, a page may initially appear secure
but later be downgraded to a warning state if mixed content is
detected. Applications should not consider this value definitive
until a NavigationCompleted event occurs.
The SecurityLevel property provides more detailed
information about the security of the page. If the Secure
property returns False, it means the connection wasn't secure,
but it doesn't provide any information as to what the underlying
reason was. The SecurityLevel property can tell you if a
secure protocol wasn't used, the site had an invalid certificate,
the page contained mixed content, or it used weak encryption.
The Certificate and Encryption properties can
provide more information about a secure connection.