Public Key Infrastructure

/ˌpiːˌkeɪˈaɪ/

noun — "the system that makes digital trust possible."

PKI, short for Public Key Infrastructure, is a framework that manages digital certificates and public-private key pairs to enable secure communication, authentication, and data integrity over networks such as the Internet. It provides the foundation for encryption, digital signatures, and identity verification in applications ranging from secure email to e-commerce and VPNs.

Hash function

/hæʃ ˈfʌŋk.ʃən/

noun — "a function that converts data into a fixed-size digital fingerprint."

Hash Function is a mathematical algorithm that transforms input data of arbitrary length into a fixed-size value, called a hash or digest. This process is deterministic, meaning the same input always produces the same hash, but even a tiny change in input drastically changes the output. Hash Functions are widely used in data integrity verification, cryptography, digital signatures, password storage, and blockchain technologies.

Cryptography

/ˈkrɪp.təˌɡræ.fi/

noun — "the art and science of keeping information secret and verifiable."

Cryptography is the study and practice of techniques for securing communication and data from unauthorized access, manipulation, or interception. It involves transforming readable data (plaintext) into an encoded form (ciphertext) using mathematical algorithms and keys, ensuring confidentiality, integrity, authentication, and non-repudiation. Cryptography underpins secure digital communication, online banking, blockchain systems, and password protection.

Spoofing

/ˈspuːfɪŋ/

noun — "tricking systems or users into believing false data is real."

Spoofing refers to the act of falsifying or impersonating data, signals, or identities to deceive a target system or user. In computing and telecommunications, spoofing can occur in multiple forms, including IP address spoofing, GPS spoofing, email spoofing, and caller ID spoofing. The objective is often to bypass security measures, redirect traffic, gather sensitive information, or manipulate a system’s behavior.

SSH

/ˌɛs ɛs ˈeɪtʃ/

noun … “a secure protocol for remote command execution and communication over untrusted networks.”

RST

/ˌɑːr-ɛs-ˈtiː/

n. “The TCP reset signal that ends a connection abruptly.”

RST, short for Reset, is a flag in the TCP (Transmission Control Protocol) header that indicates an immediate termination of a TCP connection. When a device sends a packet with the RST flag set, it signals that something went wrong or that the connection should be closed immediately without following the usual graceful teardown process.

Key characteristics of RST include:

KSK

/ˌkeɪ-ɛs-ˈkeɪ/

n. “The master key that vouches for all zone signatures in DNSSEC.”

KSK, short for Key Signing Key, is a cryptographic key used in DNSSEC (Domain Name System Security Extensions) to sign the Zone Signing Keys (ZSKs) of a DNS zone. Unlike the ZSK, which signs individual DNS records, the KSK signs the keys themselves, creating a trust chain that allows resolvers to verify the authenticity of the DNS data.