Which of the following tools can be used by a user to hide his identity? Each correct answer represents a complete solution. Choose all that apply.

A proxy server acts as an intermediary between a client and destination server, forwarding requests under the proxy's IP address and thereby concealing the user's real IP from the target.

An anonymizer is a tool or service specifically designed to strip or replace identifying information from network requests, making the user's origin untraceable to websites and services.

A rootkit is malware that hides its own presence on a compromised system by subverting OS functions - it does not conceal a user's network identity or IP address.

IPchains is a Linux kernel-level packet filtering and IP masquerading tool that can rewrite source IP addresses in outgoing packets, effectively hiding the originating host's identity on the network.

A war dialer scans ranges of telephone numbers to discover modems and remote access systems - it is a reconnaissance tool and has no function related to hiding a user's identity.