03 - Encryption, Firewalls and Mac Filtering

 1. Encryption involves:

  scrambling data so that only legitimate and authorised uses can read or access it.

  putting data into a 'crypt' which is a hidden tech box where data is secure

  using a physical key to 'crypt' (lock) data up, typically on a USB

  making data disappear so that it is encrypted (gone) forever

 2. If Encryption was used on a file, if an individual got hold of the file they would then be able to read it without the digital decryption key.



 3. In the example of encryption shown below the encryped password begins with the letters:





 4. Encryption works by scrambling the data (e.g. password) using ….

  an algorithm and a large digital number (a key)

  a hacker or clever programmer

  a turing machine

  an algorithm and an egg scrambler

 5. The algorithms used in encryption (such as the use of a hash table) mean that…

  It is quite simple to retrieve the data without the key

  It is difficult or impossible to reconstruct original data without the key

  It is not secure at all

  It is 100% secure and reconstruction of original data can never ever happen

 6. What are some of the disadvantages or potential risks of encryption?
1. If the encryption key is lost, the data is effectively gone too! 

2. The original data can easily be reconstructed using descrambling 
machines available anywhere 

3. Encrypting and decrypting data is a processor heavy task,
so causes performance issues if data is always encrypted. 

4. Encryption is against the law in certain countries 

5. It can be time consuming and awkward for user's to always 
encrypt their data. 



  4 only


 7. Encryption tends to be applied to:

  Only Names and Addresses

  Only passwords

  All types of data - absolutely everything

  Mainly confidential or sensitive data

 8. Encryption exists so that if a hacker gets into a system they cannot steal data but what can stop a hacker from getting through in the first place?
Hint: The blank below is also the answer to the question.

A __________ is often the first line of defence in network security.
A __________ will limit how data can enter or leave a system.

The rules that determine which pieces of data can go where are 
called 'packet filtering' 



  anti-virus software


 9. Firewalls allow you to block certain ports (ports are access points) as well as block _________________________

  physical people

  certain network addresses

  cable penetration

  air corruption

 10. If a user installed a game from within the network, it is possible the game will not communicate with the internet if the 'port' it is sending data from is blocked.



 11. A firewall can also block certain or specific IP addresses. For example a school may want to …..
*You may want to look up the term IP Address. Here is a basic definition. The computer you are using now has an IP Address. Every website also has an IP address because they are being stored on a server/computer. An Internet Protocol address (IP address) is a numerical label assigned to each device connected to a computer network that uses the Internet Protocol for communication. An IP address serves two principal functions: host or network interface identification and location addressing

  block all phone signals using IP disconnectors

  block student access to sites like Facebook or Youtube

  block the IP address of the whole internet (the Internet has it's unique single IP)

  block physical intruders from entering via the internet

 12. What is "Packet Sniffing"?

  Firewall employs physical human beings to 'sniff' the cables for harmful data on the cable end of the internet

  Firewalls install 'sniffing software' that specifically search for corrupted code

  Firewalls accept but then destroy all packets that have a hacker's signature on it.

  Firewall examines data packet contents coming in or out of a network- detecting dangerous code or even pre-set phrases.

 13. Firewalls can help "Denial of service" attacks where hackers send thousands or millions of requests to your server to try and overload it.



 14. Firewalls can prevent malware from leaking data back out of the network if it manages to get in.



 15. In order for any device (e.g. computer) to connect to the internet (or any network) it must have a piece of hardware called:

  a IP Connector Card (IPC)

  a Network Interface Card (NIC)

  a Hacker Prevention Card (HPC)

  a Collision Detector Card (CDC)

 16. Each NIC (Network Interface Card) has a unique number hardwired into it by the manufacturer. Fill in the blanks.
This number is called the _________________________________ 
(also called the physical address) and It allows for the device
to be _______________________. 

  Malware Accident Address (MAC Address) / Hidden

  Middle Access Adaptor (MAC Address) / Identified

  Media Access Address (MAC Address) / Secure

  Media Access Address (MAC Address) / Identified

 17. Networks can be configured to only accept connections from devices with a MAC address from an ________________________

  acrimonious individual

  accepted government

  approved list

  alter universe

 18. The process of preventing unknown devices from getting into a network and checking them against an approved list is called:

  Mac Filtering

  Device Anti Hacking

  List checking

  Network Phishing

 19. An example of Mac filtering is as follows: True or False?
A credit card machine in a shop makes contact with a credit 
card company network in order to record the transaction. 
The device (which has a mac address) will not be able to 
connect unless it has a mac address that matches up with 
the approved list of mac addresses that the company has. 

This means that people cannot create fake transactions by 
connecting to the network from a home-made device. 



 20. Read the following excerpt on end to end encryption. Which famous company uses this technology entitled: "secret conversation"?
End-to-end encryption is a powerful tool for security and safety.

It lets patients talk to their doctors in complete confidence. 

It helps journalists communicate with sources without governments listening in. 

It gives citizens in repressive regimes a lifeline to human rights advocates. 
And by end-to-end encrypting sensitive information, a cyber attack aimed at
revealing private conversations would be far less likely to succeed.
But like most technologies, it also has drawbacks: it can make it harder 
for companies to catch bad actors abusing their services or for law enforcement 
to investigate some crimes.

  Toys 'r' Us