Which cryptographic hash algorithm produces a fixed-size 128-bit digest, but is no longer considered secure against collision attacks?
Message Digest 5 (MD5) generates a 128-bit hash value. Due to discovered collision vulnerabilities, it has been deprecated for cryptographic integrity.
What type of attack involves an attacker sending thousands of TCP connection requests with spoofed source IP addresses, exhausting the server's backlog connection queue?
A SYN flood exploits the TCP 3-way handshake by leaving half-open connections in the server's SYN-RCVD queue until resources are exhausted.
Which protocols can provide confidentiality and integrity for IP-based communications?
TLS can secure application-layer communications such as HTTPS, while IPsec secures IP traffic at the network layer. Both provide confidentiality and integrity mechanisms, so A and B are correct. WPA2 protects wireless LAN access rather than serving as a general IP-layer security protocol.
What is the standard port number used by Secure Shell (SSH) for encrypted remote command-line login?
SSH runs over TCP port 22, providing encrypted terminal sessions to replace unencrypted Telnet (port 23).
Which networking utility uses ICMP Echo Request and Echo Reply messages to determine whether a remote host is operational and reachable?
The ping command transmits ICMP Type 8 (Echo Request) packets and measures the round-trip time for returned ICMP Type 0 (Echo Reply) packets.