Which of the following data does the digital signature technology encrypt to obtain a digital signature?

When configuring the security policy, ______ can control the flow based on the user.

When the firewall upgrades the signature database and virus database online through the security service center, the firewall must first be able to connect to the Internet, and secondly, the correct DNS address must be configured.

_______ is a defect in the specific implementation of hardware, software, and protocol or system security strategy, which can enable an attacker to access or destroy the system without authorization.

HTTP packets are carried by UDP, and the HTTPS protocol is based on the TCP three-way handshake, so HTTPS is more secure, and HTTPS is more recommended.