ISA-IEC-62443 Exam Dumps - ISA Cybersecurity Questions and Answers

 Layer 1 of the ISO/OSI protocol stack is the physical layer, which provides the means of transmitting and receiving raw data bits over a physical medium. It defines the electrical and physical specifications of the data connection, such as the voltage levels, signal timing, cable types, connectors, and pin assignments. It does not perform any data encryption, routing, end-to-end connectivity, framing, error checking, or user applications. These functions are performed by higher layers of the protocol stack, such as the data link layer, the network layer, the transport layer, and the application layer. References: ISO/IEC 7498-1:1994, Section 6.11; ISA/IEC 62443 Cybersecurity Fundamentals Specialist Study Guide, Section 3.1.12

The ISA/IEC 62443-3-2 standard specifies that a key output of the risk assessment process is the establishment of Target Security Levels (SL-Ts) for each security zone or conduit. These target levels define the minimum cybersecurity requirements necessary to mitigate identified risks to an acceptable level. Total risk elimination is generally not possible; instead, setting SL-Ts allows for structured, risk-based implementation of security controls.

PROFINET is the implementation of PROFIBUS over Ethernet for non-safety-related communications. It is a standard for industrial Ethernet that enables real-time data exchange between automation devices, controllers, and higher-level systems. PROFINET uses standard Ethernet hardware and software, but adds a thin software layer that allows deterministic and fast communication. PROFINET supports different communication profiles for different applications, such as motion control, process automation, and functional safety. PROFINET is compatible with PROFIBUS, and allows seamless integration of existing PROFIBUS devices and networks123

ISA/IEC 62443 is officially listed as an Informative Reference in the NIST Cybersecurity Framework (CSF). Informative References provide detailed guidance to help organizations implement the CSF's functions, categories, and subcategories.

“ISA/IEC 62443 is included in the NIST CSF Informative References to help apply risk-based cybersecurity practices to industrial control systems.”

— NIST CSF Informative Reference Catalog, Section: PR.IP and ID.RA

ISA/IEC 62443 aligns well with CSF categories such as Protect (PR) and Identify (ID), especially for operational technology environments.

Modbus TCP is a widely used protocol in industrial control systems, enabling communication between devices such as PLCs and SCADA systems over Ethernet networks. It is an adaptation of the classic Modbus protocol to TCP/IP networks and is explicitly referenced in ISA/IEC 62443 documentation as a common protocol for IACS communications. FTP, HTTP, and SMTP are general IT protocols and not primarily associated with industrial control communications.

ISASecure is a conformity assessment scheme developed under the ISA Security Compliance Institute (ISCI), an affiliate of ISA. Its primary focus is the certification of IACS (Industrial Automation and Control System) products, systems, and supplier processes for cybersecurity. The program’s aim is to facilitate and ensure the cybersecurity of automation and control systems by certifying that products and systems meet the requirements set forth in the ISA/IEC 62443 standards. ISASecure offers certifications such as ISASecure EDSA (Embedded Device Security Assurance), SSA (System Security Assurance), and CSA (Component Security Assurance), all of which are tightly mapped to the 62443 series requirements.

The ISASecure Integrated Threat Analysis (ITA) Program is a certification scheme that certifies off-the-shelf automation and control systems to the ISA/IEC 62443 series of standards1. The ITA Program consists of three main components2:

Software Development Security Assurance (SDSA): This component evaluates the security lifecycle and practices of the product supplier, such as security requirements, design, implementation, verification, and maintenance. The SDSA certification is based on the ISA/IEC 62443-4-1 standard.

Functional Security Assessment (FSA): This component verifies the security functions and features implemented in the product, such as identification and authentication, access control, encryption, audit logging, and security management. The FSA certification is based on the ISA/IEC 62443-4-2 standard.

Communications Robustness Testing (CRT): This component tests the resilience of the product against network attacks, such as denial-of-service, fuzzing, spoofing, and replay. The CRT certification is based on the ISA/IEC 62443-4-2 and ISA/IEC 62443-3-3 standards .

According to the OSI model, the physical address is assigned in the layer 2, also known as the data link layer. The physical address is a unique identifier for each device on a network, such as a MAC address or a serial number. The data link layer is responsible for transferring data between adjacent nodes on a network, using the physical address to identify the source and destination of each frame. The data link layer also provides error detection and correction, flow control, and media access control. References: ISA/IEC 62443 Cybersecurity Fundamentals Specialist Exam Prep, section 2.2; ISA/IEC 62443 Standards to Secure Your Industrial Control System, section 3.1.2.

Foundational Requirement 1 (FR 1) in the ISA/IEC 62443 series is titled “Identification and Authentication Control (IAC)”. Its purpose is to control access to selected devices by ensuring that only authenticated and authorized users or systems can interact with critical IACS components.

“FR 1 – Identification and Authentication Control (IAC): This foundational requirement ensures that all users and components interacting with the system are uniquely identified and authenticated before access is granted.”

— ISA/IEC 62443-3-3:2013, Clause 4.2.1 – FR 1

This foundational layer supports higher-level security goals like use control, confidentiality, and system integrity.

Within the context of the Cyber Security Management System (CSMS) as defined in ISA/IEC 62443-2-1, the primary stakeholders include operations staff (responsible for system operations), IT security staff (for information technology and cybersecurity controls), and physical security staff (for site access and physical barriers). Marketing staff are not typically listed as stakeholders in the design, implementation, or maintenance of the CSMS, since their role does not directly influence the security posture of industrial control systems. This is outlined in the roles and responsibilities sections of the standard.