PGP Compression, Steganography & Network Security Tools

Posted on Feb 23, 2026 in Computer Engineering

PGP Compression (Ultra-Compact Answer)

PGP performs compression before encryption to reduce message size and improve security. Compression removes redundancy so encrypted output becomes smaller, faster to transmit, and harder to analyze because repeated patterns disappear. The most commonly used algorithm is ZIP (LZ77-based) inside PGP. The process is: Message → Compression → Encryption → Transmission → Decryption → Decompression. Compression helps hide patterns in plaintext, making cryptanalysis more difficult and reducing overall bandwidth.

Benefits:

Smaller message size
Faster transmission
Removes plaintext patterns → stronger security
Saves storage
Improves performance of encryption

Drawbacks:

Slight processing overhead
Ineffective for already compressed files (video, ZIP)

Steganography

Steganography is the technique of hiding secret data inside a normal-looking file (image, audio, video, text) so that the existence of the hidden message is not detectable. Unlike cryptography, which hides the content, steganography hides the presence of communication.

How it Works (Short):

Secret data is embedded into the least significant parts of a cover file (e.g., image pixels or audio samples) without visibly changing the cover. The receiver extracts the hidden message using the same method. Process: Cover File + Secret Data → Embedding → Stego File → Extraction → Secret Message.

Common Methods:

LSB (Least Significant Bit): Hide bits of secret data in pixel LSBs (most used).
Masking & Filtering: Embed information into significant image areas.
Transform Domain (DCT/DWT): Hide data in frequency coefficients (JPEG, audio).
Audio Steganography: Hide data in sound samples.
Video Steganography: Use frames to embed data.

Uses:

Secret communication
Watermarking
Copyright protection
Covert channels
Forensic security

Advantages:

Hides existence of data
Difficult to detect
Supports many file types
Useful for copyright & authentication
Can combine with cryptography for double security

Disadvantages:

Low capacity (small amount of data only)
If detected, message is exposed
Vulnerable to compression & editing
Large files required for hiding more data

Example: A secret text is hidden inside an image by altering the last bit of pixel values; the image looks the same but carries hidden data.

DoS Attack Tools (Ultra-Compact Answer)

DoS attack tools are programs used to flood a target system with excessive traffic, exhausting its bandwidth, CPU, or memory so legitimate users cannot access the service.

Common DoS Tools:

LOIC (Low Orbit Ion Cannon): Simple tool for TCP/UDP/HTTP flooding.
HOIC (High Orbit Ion Cannon): More powerful HTTP flooder with booster scripts.
Hping / Hping3: Packet crafter used to send customized TCP/UDP/ICMP floods.
Slowloris: Sends slow, partial HTTP headers to exhaust server threads.
R-U-Dead-Yet (RUDY): Slow HTTP POST attack targeting web forms.
Tor’s Hammer: Slow POST attack using TOR to hide identity.
Xoic: Basic GUI tool for UDP, TCP, and HTTP DoS floods.
UDP Flood Tools: Generate high-volume UDP packets.
Smurf Attack Tools: Spoofed ICMP broadcasts used to overwhelm the victim.
Ping of Death Tools: Send oversized ICMP packets to crash older systems.

Footprinting Tools

Footprinting tools are used in ethical hacking to gather initial information about a target system, network, or domain before an attack or security assessment. Their goal is to collect data like IPs, DNS records, server info, emails, OS details, and network structure.

Common Footprinting Tools:

Whois: Gets domain owner details, registrar info, IP ranges.
nslookup: Retrieves DNS records (A, MX, NS).
dig: Advanced DNS query tool for DNS footprinting.
Traceroute / Tracert: Maps route and hops to target.
Nmap: Finds open ports, OS details, services; active footprinting.
theHarvester: Collects emails, subdomains, hosts from search engines & public sources.
Maltego: Graph-based tool for mapping people, domains, IPs, OSINT links.
Shodan: Search engine for internet-connected devices; reveals services & vulnerabilities.
Google Dorking: Uses advanced Google operators to gather exposed information.
Censys: Finds certificates, domains, open services.
Recon-ng: Framework for web-based reconnaissance.
Social Engineering Tools: Collect info from social media (LinkedIn, Facebook).

Trojan Detection Tools (Ultra-Compact Answer)

Trojan detection tools are security programs used to identify, block, and remove Trojan malware that hides inside systems, steals data, or gives remote access to attackers. These tools scan files, monitor system processes, check network connections, and detect suspicious behavior linked to Trojan activity.

Common Trojan Detection Tools:

Malwarebytes Anti-Malware: Detects & removes Trojans, rootkits, spyware.
Kaspersky Anti-Virus: Strong Trojan detection using behavioral analysis.
Avast / AVG: Real-time scanning, blocks Trojan downloads & executions.
Windows Defender: Built-in protection; detects common Trojans via signature + behavior.
Spybot Search & Destroy: Removes Trojan spyware and malicious scripts.
ESET NOD32: Lightweight antivirus with high Trojan detection rate.
Norton Security: Detects Trojan backdoors, RATs, and remote control tools.
McAfee: Real-time scanning with cloud-based Trojan signature checks.
SUPERAntiSpyware: Detects Trojan droppers, keyloggers, spyware components.
Trend Micro HouseCall: Online scanner to detect hidden Trojans.
Rootkit Revealer: Detects Trojans hidden as rootkits.
TCPView / CurrPorts: Shows suspicious open ports used by Trojan backdoors.
Process Explorer: Identifies unknown or malicious processes running in the background.
Wireshark: Captures suspicious outbound traffic from Trojan-infected systems.

Wireshark / tcpdump

Wireshark and tcpdump are packet-capture and network-analysis tools used to monitor, record, and analyze network traffic. They help detect attacks, troubleshoot issues, and understand network behavior.

Wireshark:

A GUI-based network protocol analyzer that captures live packets and displays them in detailed, decoded form. Supports filters, color coding, deep inspection of TCP, UDP, HTTP, DNS, SSL, etc. Useful for detecting DoS attempts, suspicious IPs, ARP spoofing, and protocol misuse.

tcpdump:

A command-line packet sniffer used to capture packets directly from the network interface. Faster and lightweight compared to Wireshark; shows raw packet headers and fields. Supports powerful capture filters (BPF). Often used for quick diagnostics, security monitoring, and server-side packet capture.

Difference (Compact):

Wireshark = GUI, deep analysis, visual filters.
tcpdump = CLI, fast capturing, raw packet data.
Wireshark is detailed; tcpdump is lightweight and terminal-based.