IAS

Standard

A written set of rules or guidelines for how things should be done. Some are strong and widely accepted, while others just reflect market or vendor influence.

Policy

Created to support the organization’s mission, vision, and goals. To be effective, it must be shared, understood, and accepted by everyone in the organization.

Informal - de facto standards

These are widely used because the market adopts them. They are also known as market-driven standards.

Formal - de jure standards

These are officially approved by a recognized organization through formal procedures, giving them legal or official status.

Mission

Written statement of organizations purpose

Vision

Written statement of organization goals

Strategic Plan

Written statement of moving the organization toward its mission

Enterprise Information Security Policy (EISP)

It is a high-level document that defines the organization’s overall approach to IT security. Created with executive input, it’s usually 2–10 pages long and covers compliance, assigned responsibilities, and enforcement through penalties or disciplinary actions.

Issue Specific Security Policy

It focuses on specific technology areas and is updated regularly. It states the organization’s stance on an issue and includes rules on access, equipment use, system management, violations, updates, and legal limits.

System-Specific Policy

It provides detailed rules and steps for configuring or maintaining systems. They are often written as standards and procedures.

Access Control List

It manage who can access what. They control access based on user, device, time, and location. It regulate actions like reading, writing, modifying, or copying data, and are based on a person’s identity and permissions.

Rule Policies

It defines specific system operations. They may not involve users directly and usually include scripts that tell systems how to handle certain types of information.

Policies

These are living documents that evolve over time. They must be well-managed, shared effectively, and kept up to date. A Policy Administrator oversees this process, often with support from a non-technical champion or manager.

Review

It should be scheduled and happen regularly to keep policies effective in a changing environment. The process should be clearly defined and documented, often starting with one person drafting updates based on current practices and recommendations.

Information Classification

It helps protect sensitive data. Policies are often labeled at least as “internal use only.”

Information Security Blueprint

It is a detailed plan for designing and implementing security policies, training, and technical controls. It expands on the security framework and outlines tasks and their order.

Blueprint of an Information Security System

It is built from analyzing key documents, standards, and resources. It serves as a starting point for learning how to create security plans.

Managerial Control

It guides the overall direction and scope of security operations. They focus on process design, risk management, legal compliance, and are implemented by security administrators to ensure effective security functionality.

Operational Control

It ensures day-to-day security works as planned. They cover disaster recovery, incident response, physical and personnel security, data integrity, system maintenance, and training. They also protect input/output processes and help raise awareness.

Technical Control

It focus on the tools and technologies used to protect systems. They handle identification, authentication, authorization, and accountability. They also include audits, cryptography, and classifying users and assets.

Defense in Depth

It means using multiple layers of security—through policies, training, and technology

Security Perimeter

The point at which an organization’s security protection ends and the outside world begins

Firewall

It is a specially configured device that filters incoming and outgoing information. It’s typically placed at or just behind the gateway router to protect the network perimeter.

Demilitarized Zone

It is a buffer zone between a private network and the outside world. It helps protect against external attacks, and web servers are often placed here for added security.

Proxy Server

It acts on behalf of another system. It’s set up to appear as a web server with its own domain name, retrieves and sends data, and often stores content as a cache to improve performance.

Host-Based Intrusion Detection System

It is installed directly on the machine it protects. It monitors activity on that host to detect suspicious behavior or attacks.

Network-Based Intrustion Detection System

It monitors traffic patterns across the network to detect unusual activity. It relies on a database of past behavior, may use machine learning, and can draw insights from similar networks to improve detection.

Security Education, Training, and Awareness

It addresses employee errors—one of the top threats. Its goals are to raise awareness, build skills, and develop deep knowledge to support, design, or run security programs effectively.

Continuity Strategies

It ensures systems stay available, even during attacks. Since the risk is high, managers must be prepared.

Incident Response Plan

Immediate reaction to incidents

Disaster Recovery Plan

Restores systems after disruption

Business Continuity Plan

Keeps essential functions running, often at an alternate site

Champion

A senior manager who supports and promotes the project.

Project Manager

Oversees planning, ensures a solid plan, and manages resources.

Team Members

Representatives from business, IT, and security—usually managers or their delegates.

Business Impact Analysis

It assesses how different attacks could affect the organization.

Business Unit Analysis

It focuses on identifying and ranking key business functions within each unit.

Incident Response Planning

It involves identifying, classifying, and responding to incidents.

Incident Detection

It involves recognizing signs of a possible attack.

Incident Containment Strategies

It aims to limit damage quickly.

Disaster Recovery Plan

It provides a clear guide during a disaster

Crisis Management

It focuses on people and business viability during and after a disaster.

Continuity Strategies

It offers various options for maintaining operations during disruptions.

Hot site, Warm site, Cold site

Time-share

Shared facility used as needed

Service bureau

Third party handles operations

Mutual Agreement

Partner organizations support each other during crises

Off-Site Disaster Data Storage

It ensures critical data is stored safely away from the main site. This allows quick transfer and setup of systems at a new location to resume operations after a disaster.

Model for a Consolidated Contingency Plan

It combines all response plans into one clear document. It helps streamline planning, especially for smaller organizations, and promotes regular testing and use.

Firewall

It acts as a barrier between trusted and untrusted networks.

Network Firewall

It is placed between trusted and untrusted networks, like internal systems and the internet. It monitors and controls traffic using set rules, checking details like IP addresses, protocols, and ports to block threats and unwanted data.

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Network Firewall

Host-Based Firewall

It is a software installed on a single device within a network. It provides targeted protection by monitoring that device’s traffic, blocking malware, viruses, and other threats from entering or leaving the system.

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Host-Based Firewall

Hardware Firewall

It is a physical device positioned between a computer or network and the internet. It works independently from any host, inspecting all traffic to enforce security rules and block unauthorized access.

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Hardware Firewall

Software Firewall

It is a firewall in a software form factor rather than a physical appliance, which can be deployed on servers or virtual machines to secure cloud environments.

Container Firewall

It is a software version of a next-generation firewall that is purpose-built for Kubernetes environments.

Virtual Firewall

It is a software-based firewall used in virtual and cloud environments. It secures both north-south (external) and east-west (internal) traffic. Also known as a “cloud firewall,” it provides advanced threat prevention through features like microsegmentation, helping to isolate and protect workloads within data centers and cloud networks.

Cloud Firewall

These are virtual, software-based firewalls deployed in cloud environments. They filter malicious traffic and are often delivered as Firewall-as-a-Service (FWaaS).

Managed Service Firewall

These are software firewalls offered as a managed service, similar to SaaS. They provide application-level (Layer 7) security and allow organizations to outsource firewall management, reducing the need for in-house oversight while maintaining strong protection.

Internal Firewall

It operates within the network to monitor traffic between internal devices, identifying threats that may have bypassed outer defenses, and follows a Zero Trust approach—assuming nothing inside the network is automatically trusted.

Distributed Firewall

It protects an organization’s infrastructure by operating across the network, using multiple devices to monitor and control both internal and external traffic.

Intern

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Distributed Firewall

Perimeter Fir

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Perimeter Firewall

Next Generational Firewall

It builds on traditional firewall functions by adding advanced features like application traffic control, intrusion prevention, and cloud-based threat intelligence to deliver more comprehensive security.

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Next Generational Firewall

Packet Filtering Firewall

It operates at the network layer, regulating data packet flow between networks. These firewalls rely on pre-defined rules that evaluate specific attributes of the packets, such as source IP, destination IP, ports, and protocols.

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Packet Filtering Firewall

Circuit Level Gateway

It operates at the session layer, managing and verifying the handshaking process for TCP and UDP connections to ensure secure communication.

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Circuit Level Gateway

Web Application Firewall

It serves as a specialized layer of protection for web applications, web servers, and APIs.

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Web Application Firewall

Proxy Firewall

It is a vital network defense mechanism, operating at the application layer. Also referred to as an application firewall or gateway firewall, it primarily functions as an intermediary, filtering messages between computer systems and external servers.

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Proxy Firewall

Stateful Inspection Firewall

It analyze the context of incoming and outgoing traffic, ensuring only safe data packets traverse the network. Located at Layers 3 and 4 of the Open Systems Interconnection (OSI) model, their primary function is to filter traffic based on its state and context.

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Stateful Inspection Firewall

Network Address Translation

It is a method used in networking where private (internal) IP addresses are translated into a public IP address before packets are forwarded to the external network (typically, the internet).

It hides the internal network structure from the outside world and conserves public IP addresses.

Cryptography

It is the study and practice of protecting information through secure communication methods, ensuring that unauthorized parties cannot access the data. It involves creating and analyzing protocols to keep shared information confidential, following key principles of information security.

Secure Communications

It ensures that data shared between two parties remains inaccessible to unauthorized individuals, known as adversaries.

Adversary

a malicious entity, which aims to retrieve precious information or data thereby undermining the principles of information security, data confidentiality, data integrity

Confidentiality

It refers to certain rules and guidelines usually executed under confidentiality agreements which ensure that the information is restricted to certain people or places.

Data Integrity

It ensures that information remains accurate and consistent throughout its entire lifecycle.

Authentication

It confirms that the data or identity being presented truly belongs to the user.

Non-repudiation

It guarantees that a person or party cannot deny the authenticity of their actions, such as sending a message or signing a document.

Symmetric Key Cryptography

It uses a single secret key for both encrypting and decrypting messages.

Data Encryption Standard

It is a symmetric block cipher that encrypts data in fixed-size blocks of 64 bits, producing output of the same size.

Advanced Encryption Standard

It is a widely trusted encryption algorithm developed by NIST in 2001 to secure data by converting it into unreadable form without the correct key.

Blowfish

It is a symmetric block cipher developed by Bruce Schneier in 1993 as a faster and more secure alternative to DES.

Asymmetric Key Cryptography

It is also called public-key cryptography, uses a pair of keys—one public and one private—for encryption and decryption. It solves the key distribution problem but is much slower than symmetric methods, making it less suitable for large amounts of data.

Rivest-Shamir-Adleman

It is a public-key cryptography algorithm developed in 1977 by Ron Rivest, Adi Shamir, and Leonard Adleman. It uses two keys: a public key for encryption and a private key for decryption.

Elliptic Curve Cryptography

It offers the same level of security as RSA but with much shorter key sizes.

ElGamar Encryption Algorithm

It is a public-key encryption algorithm developed by Taher ElGamal in 1985. It uses asymmetric keys for secure communication and is based on the difficulty of solving discrete logarithms in a cyclic group.

Digital Signature Algorithm

It is a federal standard introduced by NIST in 1991 to verify the authenticity and integrity of messages, software, or digital documents.

Hashing

It is the process of converting plain text into a fixed-size value using a hash function.

Hash Function

It is a mathematical algorithm that converts data of any size into a fixed-size output

Message Digest 5

It is a cryptographic hash function algorithm that takes the message as input of any length and changes it into a fixed-length message of 16 bytes.

Secure Hash Algorithm 1

It is a cryptographic hash algorithm developed by the U.S. National Security Agency that generates a 160-bit (20-byte) hash value, often shown as a 40-digit hexadecimal number called a message digest. Once widely used, it has been considered insecure since 2005 due to vulnerabilities.

Secure Hash Algorithm 2

It is a cryptographic hash function that produces 224, 256, 384 or 512 bits hash value