INFO ASS

Cryptography

is the practice of protecting information by transforming it into a form that unauthorized people cannot easily understand or use. Its primary purpose is to protect the confidentiality, integrity, authentication, and authenticity of information.

Plaintext

the original readable information.

Ciphertext

the encrypted or scrambled version of the information.

Encryption

converting plaintext into ciphertext.

Decryption

converting ciphertext back into plaintext.

Key

a value used by a cryptographic algorithm to encrypt or decrypt information.

Symmetric Encryption

Uses the same key for encryption and decryption.

Asymmetric Encryption

Uses a pair of keys

Public key

can be shared with others.

Private key

must be kept secret.

Hashing

— converts data into a fixed-length value called a —. Unlike encryption, — is generally designed to be one-way.

Digital Signatures

use cryptographic techniques involving keys

Social Engineering

refers to techniques used to manipulate or deceive individuals into revealing information, performing an action, or providing access that should not be granted.

Phishing

Fraudulent messages designed to trick users into revealing information or performing an unsafe action.

Spear Phishing

A more targeted phishing attack directed at a particular person or organization.

Pretexting

The attacker creates a false story or identity to persuade someone to provide information.

Baiting

The attacker offers something attractive to encourage the victim to perform an unsafe action

Tailgating

An unauthorized person follows an authorized person into a restricted area.

Quid Pro Quo

The attacker offers a supposed benefit or service in exchange for information or access

Data integrity

is the assurance that data remains accurate, complete, consistent, and trustworthy throughout its entire lifecycle. In information security, integrity helps ensure that information has not been altered, deleted, corrupted, or manipulated without authorization.

refers to maintaining the correctness and reliability of information.

Physical Integrity

Protects data from physical damage or loss.

Logical Integrity

Ensures that data remains correct and consistent within a system.

Database Integrity

Database systems use several controls to maintain reliable data.

Entity Integrity

Ensures that every record can be uniquely identified.

Referential Integrity

Ensures that relationships between tables remain valid.

Domain Integrity

Ensures that values entered into a field follow predefined rules.

User-Defined Integrity

Rules established according to an organization's requirements.

Digital Certificate

is an electronic credential that associates an identity with a public key.

It is commonly issued by a trusted Certificate Authority (CA).

The "Five Nines" Concept

refers to a target of 99.999% availability. It means that a service is intended to be operational almost all the time.

High Availability (HA)

Systems are designed to minimize downtime through mechanisms such as:

• Redundant servers

• Failover systems

• Load balancing

• Backup systems

• Multiple network connections

Fault Tolerance

A — system continues operating even when some components fail.

Disaster Recovery

— focuses on restoring systems after major disruptions.

Business Continuity

— is broader than disaster recovery. It focuses on keeping critical business operations functioning during and after disruptions.

Cloud Resilience

Modern cloud environments may distribute applications and data across:

• Multiple servers

• Availability zones

• Data centers

• Geographic regions

Database Controls

Keep data correct and consistent

Digital Signatures & Certificates

Help verify authenticity and integrity

High Availability & Resilience

Help ensure information systems remain accessible and operational

Authenticity

who signed the data

Integrity

whether the data was changed

Non-repudiation

provides evidence associated with the signer's action

public key

The recipient can use the signer's — to verify the signature.