Network Security

What is Data Encryption in Transit for Databases?

Data encryption in transit protects data while it moves across a network — between an application and the database, between replicas, or during a backup transf…

What is a Firewall?

A firewall is a network security system that monitors and controls incoming and outgoing traffic based on a defined set of rules, sitting between a trusted int…

What is a VPN?

A VPN (Virtual Private Network) creates an encrypted tunnel between a device and a remote server, so traffic looks like it originates from that server and cann…

What is SSL/TLS?

SSL/TLS is a cryptographic protocol that encrypts data in transit between a client and server, verifies the server’s identity using certificates, and ensures t…

What is SNMP (Simple Network Management Protocol)?

SNMP (Simple Network Management Protocol) is an Application-layer protocol used to monitor and manage network devices — routers, switches, servers, printers —…

What is FTP (File Transfer Protocol)?

FTP (File Transfer Protocol) is an application-layer protocol for transferring files between a client and a server over a network, using a separate control con…

What is SFTP (SSH File Transfer Protocol)?

SFTP (SSH File Transfer Protocol) is a secure file transfer protocol that runs entirely over a single encrypted SSH connection on port 22, providing file opera…

What is IMAP (Internet Message Access Protocol)?

IMAP (Internet Message Access Protocol) is an application-layer protocol that lets an email client read and manage messages that remain stored on the mail serv…

What is POP3 (Post Office Protocol version 3)?

POP3 (Post Office Protocol version 3) is an application-layer protocol for retrieving email that traditionally downloads messages from the mail server to a sin…

What is Telnet?

Telnet is an application-layer protocol that provides a text-based, interactive terminal session to a remote host over TCP port 23, sending everything — includ…

What is SSH (Secure Shell)?

SSH (Secure Shell) is an encrypted application-layer protocol, typically running on TCP port 22, that provides secure remote login, command execution, and file…

What is LDAP (Lightweight Directory Access Protocol)?

LDAP (Lightweight Directory Access Protocol) is an application-layer protocol, typically running on TCP port 389 (or 636 for LDAPS), used to query and modify h…

What is a SYN Flood Attack?

A SYN flood is a denial-of-service attack that sends a large number of TCP SYN segments, often with spoofed source addresses, to exhaust a server's connection…

What is DNS over HTTPS (DoH)?

DNS over HTTPS (DoH) is a protocol that carries standard DNS queries and responses inside encrypted HTTPS connections instead of sending them as plaintext UDP…

Symmetric vs Asymmetric Encryption

Symmetric encryption uses one shared secret key for both encrypting and decrypting data, making it fast but requiring a secure way to distribute that key, whil…

What is Public Key Infrastructure (PKI)?

Public Key Infrastructure (PKI) is the set of roles, policies, and systems needed to create, distribute, validate, and revoke digital certificates that bind a…

What are Digital Certificates?

A digital certificate is an electronic document, typically in X.509 format, that binds a public key to an identity (such as a domain name or organization) and…

Explain the TLS Handshake in Detail

The TLS handshake is the negotiation phase where a client and server agree on a cipher suite, authenticate the server (and optionally the client) via certifica…

What is IPsec and How Does It Secure IP Traffic?

IPsec (Internet Protocol Security) is a suite of protocols that authenticates and encrypts IP packets at the network layer, most commonly used to build VPN tun…

What is a DDoS Attack and How Is It Mitigated?

A DDoS (Distributed Denial of Service) attack overwhelms a target’s network, server, or application with traffic from many distributed sources simultaneously,…

What is a Man-in-the-Middle Attack?

A man-in-the-middle (MITM) attack is when an attacker secretly positions itself between two communicating parties, intercepting, and potentially altering, traf…

What is Packet Sniffing?

Packet sniffing is the practice of capturing and inspecting raw network traffic as it passes over a wire or wireless link, typically by putting a network inter…

What is Port Scanning?

Port scanning is the technique of systematically probing a target host’s TCP or UDP ports to discover which ones are open, closed, or filtered, revealing what…

VPN Types Explained: Remote Access vs Site-to-Site

A VPN (Virtual Private Network) creates an encrypted tunnel over an untrusted network like the internet, and the two most common types are remote-access VPNs,…