ISA-IEC-62443 Exam Questions & Answers

Correct Answer: B

An asymmetric key is a feature of asymmetric cryptography, also known as public-key cryptography, which is a method of encrypting and decrypting data using two differentkeys: a public key and a private key. The public key can be shared with anyone, while the private key must be kept secret by the owner. The public key and the private key are mathematically related, but it is computationally infeasible to derive one from the other. Asymmetric cryptography can be used for various purposes, such as digital signatures, key exchange, and encryption. For example, if Alice wants to send a message to Bob, she can use Bob's public key to encrypt the message, and only Bob can decrypt it using his private key. Alternatively, if Bob wants to prove that he is the author of a message, he can use his private key to sign the message, and anyone can verify it using his public key. Asymmetric cryptography has some advantages over symmetric cryptography, which uses the same key for both encryption and decryption. For instance, asymmetric cryptography does not require a secure channel to distribute the keys, and it can provide non-repudiation and authentication. However, asymmetric cryptography also has some drawbacks, such as higher computational complexity, larger key sizes, and higher network overhead. References: ISA/IEC 62443-3-3:2018, Section 4.2.3.6.1, Cryptography1 ISA/IEC 62443-4-2:2019, Section 4.2.3.6.1, Cryptography ISA/IEC 62443 Cybersecurity Fundamentals Specialist Study Guide, Section 5.3.1, Cryptography ISA/IEC 62443 Cybersecurity Fundamentals Specialist Exam Specification, Section 5.3.1, Cryptography

Correct Answer: C

The reference model provides the overall conceptual basis in the design of an appropriate security program. It defines the common terminology, concepts, and models that can be used by all stakeholders responsible for IACS security. The reference model describes the general characteristics of IACS, the typical threats and vulnerabilities, the security lifecycle phases, and the security levels. The reference model also introduces the concepts of zones and conduits, which are used to group and isolate assets with similar security requirements and to control the communication between them. Referenceshttps://www.cisco.com/c/en/us/td/docs/solutions/Verticals/IoT_Security_L ab/IEC62443_WP.pdf https://www.cisco.com/c/en/us/td/docs/solutions/Verticals/IoT_Security_Lab/IEC62443_WP .pdf

Correct Answer: A

The File Transfer Protocol (FTP) is an application layer protocol that moves files between local and remote file systems. It runs on top of TCP, like HTTP. To transfer a file, 2 TCP connections are used by FTP in parallel: control connection and data connection. The control connection is used to send commands and responses between the client and the server, while the data connection is used to transfer the actual file. FTP is one of the standard communication protocols defined by the TCP/IP model and it does not fit neatly into the OSI model. However, since the OSI model is a reference model that describes the general functions of each layer, FTP can be considered as an application layer protocol in the OSI model, as it provides user services and interfaces to the network. The application layer is the highest layer in the OSI model and it is responsible for providing various network services to the users, such as email, web browsing, file transfer, remote login, etc. The application layer interacts with the presentation layer, which is responsible for data formatting, encryption, compression, etc. The presentation layer interacts with the session layer, which is responsible for establishing, maintaining, and terminating sessions between applications. The session layer interacts with the transport layer, which is responsible for reliable end-to-end data transfer and flow control. The transport layer interacts with the network layer, which is responsible for routing and addressing packets across different networks. The network layer interacts with the data link layer, which is responsible for framing, error detection, and medium access control. The data link layer interacts with the physical layer, which is responsible for transmitting and receiving bits over the physical medium. References: File Transfer Protocol (FTP) in Application Layer1 FTP Protocol2 What OSI layer is FTP?3