Network Security Flashcards
Why are newer DCS and SCADA systems more vulnerable to outside threats than the systems of the past?
Older control systems were vendor specific and came with proprietary software and hardware. This made these control systems more secure.
Modern control systems use standardized protocols derived from Microsoft and Unix. This is cheaper but leaves the networks more vulnerable to threats.
What is the purpose of Security Filtering?
An approach that allows outside entities securely connect to a private network
What is a firewall?
Network tool that prevents unauthorized devices from entering a private secured network. These can be stand alone devices or combined with hardware like routers and gateways.
What is responsible for 80% of firewall breaches?
Incorrect firewall configuration
What are the 2 most common firewall configuration mistakes?
Making IP addresses or management interfaces visible
How can a firewall be more secured?
1) Update with latest firmware
2) Use unique passwords
3) Have a proper configuration
4) Never using shared accounts
5) Restricting traffic
6) Disabling Simple Network Management Protocol
What is an access control list?
Exist in routers or firewalls and are designed to conform to rules that restrict access to the network for specific users
What is MAC filtering?
An Access Control List rule that allows only remote MAC addresses to access the network.
What is IP filtering?
An ACL rule that filters access by IP addresses.
What is a VPN?
Virtual Private Network: strategy that creates a private network within a public network by using tunneling and encryption.
What is encryption?
Process of encoding data that can not be deciphered by unauthorized entities. Data is ran through an algorithm that generates “ciphertext”.
Describe symmetric or Private Key encryption.
Uses the same key that is known only to the sender and receiver that encrypts and decrypts data.`
Describe Asymmetric or Public Key ecryption.
Use a public key and a private key to encrypt and decrypt data. Public key encrypts the data and the private key is used for decryption. This method is not suited for large messages due to slow speed.
What is the Industry standard for encryption?
Industry uses Advanced Encryption Standard (AES) that utilizes symmetric encryption and an algorithm to apply multiple rounds of encryption to produce a 128 bit key.
Give an example where Remote Access might be used in an Industrial Control Network environment.
Telecommuting
