Test 3 - Review Questions

Question 1

Can you undo a hash function?

Answer 1

No

Question 2

What are different types of ciphers?

Answer 2

Stream and Block

Question 3

What is the difference between Stream and Block ciphers?

Answer 3

Stream: One character at a time
Block: Group of characters at a time

Question 4

What is the Caesar Cipher?

Answer 4

The Caesar cipher is one of the earliest known and simplest ciphers. It is a type of substitution cipher in which each letter in the plaintext is ‘shifted’ a certain number of places down the alphabet. For example, with a shift of 1, A would be replaced by B, B would become C, and so on.

Question 5

What is a block cipher used in the real world?

Answer 5

DES, AES

Question 6

What does AES stand for?

Answer 6

Advanced Encryption Standard

Question 7

What does DES stand for?

Answer 7

Data Encryption Standard

Question 8

What is the piece of math used in AES/DES?

Answer 8

XOR

Question 9

What is XOR?

Answer 9

(XOR) Exclusive or or exclusive disjunction is a logical operation that outputs true only when inputs differ (one is true, the other is false). Represented with ^ (ie. P^Q)

Question 10

What is another way of saying, a XOR b?

Not on the test, just for understanding

Answer 10

a XOR b = (a OR b) AND (not a AND b)

Question 11

How is RSA different from AES?

Answer 11

1. RSA is related to prime numbers and factoring them

2. RSA is asymmetric, while AES is symmetric

Question 12

What result will you get for

Encode(public, pt)?

Answer 12

ct

Question 13

What result will you get for

Encode(private, ct)?

Answer 13

pt

Question 14

Let’s say Alice sends Bob a msg, how would Bob know it came from Alice?

Answer 14

1. Bob generates Public(Bob), Private(Bob)
2. 5. Alice generates Public(Alice), Private(Alice)
3. Bob tells everyone Public(Bob)
4. 5. Alice tells everyone Public(Alice).
5. Alice Encode [Public(Bob), msg] to get ct
6. Alice sends Bob cipher text
7. Bob calculates encode [Private(Bob), ct] to set message.

Question 15

Let’s say Alice sends Bob a msg, and she encodes it. How would Bob decode it?

Alice
Encode(Public(Bob))
Encode(Private(Alice))

Answer 15

1. Bob would Encode(Public(Alice))

2. Encode(Private(Bob), CT)

Question 16

Let’s say Alice sends Bob a msg, how would she generate it?

Answer 16

1. Bob generates Public(Bob), Private(Bob)
2. Bob tells everyone Public(Bob)
3. Alice Encode [Public(Bob), msg) to get ct
4. Alice sends Bob cipher text
5. Bob calculates encode [Private(Bob), ct] to set message.

Question 17

What is more expensive AES or RSA?

Answer 17

RSA, has more CPU cycles due to higher computations.

Question 18

When do we use encryption in our daily lives?

Answer 18

1. E-Commerce, ie. using credit card numbers.

2. Check emails

Question 19

When you see a lock icon right before your URL on a browser, what web protocol is being applied?

Answer 19

SSL

Question 20

What is difference between authentication and authorization?

Answer 20

Authentication: Are you who you say you are? (ie. Username/PW)
Authorization: What level of access do you have?

Question 21

Are passwords stored in a database? If not, what is?

Answer 21

Passwords are not stored, hashed version of the passwords are stored.

Question 22

What is a hash comprised of?

Answer 22

Password + Salt

Question 23

What is salt?

Answer 23

Salt is random data that is used as an additional input to a one-way function that “hashes” data, a password or passphrase. Salts are used to safeguard passwords in storage. Can be based on various fields tied to an account (account, creation of account, time/date)

Question 24

If a person inputs their login credentials and hist send, what is happening in the background?

Answer 24

1. A script looks up user, salt, hash password from database.
2. Calculate hash(password+salt)
3. Compare hashpassword and hash(password+salt).

Question 25

What types of malware is there?

Answer 25

Trojan horses, worms

Question 26

What do keyloggers do?

Answer 26

Stores all keys inputted (ie. passwords, credit card details).

Question 27

What languages do we use to build E-commerce websites and what do they do?

Answer 27

1. HTML = Hypertext markup language = used for content, structure, webpage
2. CSS = Cascading style sheet = styling
3. JavaScript = interactive (user-side)
4. PHP = Personal Homepage = dynamically create the webpages (server-side)
5. SQL = database access

Question 28

What is the data hierarchy in a relational database?

Answer 28

Database
Table
Field

Question 29

An ethical approach that is based on duty and obligations is called _____:

Answer 29

deontology

Question 30

What are the 3 parts in a dialectic exchange?

Answer 30

Thesis, antithesis, synthesis

Question 31

What are is Kant’s 2nd categorical imperative?

Answer 31

“The second formulation of the categorical imperative is called the Formula of the End in Itself: “Act in such a way that you always treat humanity, whether in your own person or in the person of any other, never simply as a means, but always at the same time as an end.”

Question 32

What is consequentialism?

Answer 32

is the class of normative ethical theories holding that the consequences of one’s conduct are the ultimate basis for any judgment about the rightness or wrongness of that conduct. Thus, from a consequentialist standpoint, a morally right act (or omission from acting) is one that will produce a good outcome, or consequence.

Question 33

What is a database?

Answer 33

a structured set of data held in a computer, especially one that is accessible in various ways.

Question 34

Ask these questions when facing an ethical consequence

Answer 34

1. Who are the stakeholders in this situation?
2. What does each of them have to gain/lose?
3. What duties and responsibilities are important?
4. Can you think of an analogous situation? Does it clarify the situation?
5. Make a decision or come to a dialectic exchange

Question 35

What are tables made up of?

Answer 35

Records

Question 36

What is stored in a table?

Answer 36

Each table contains RECORDS, which you enter into the database. All of your Clients, Images, Invoices, etc., are considered records (identified by an ID).

Question 37

What is stored in a record?

Answer 37

Within each record are data FIELDS. Fields are the individual parts that contain information about the record.

Question 38

What are records made up of?

Answer 38

Fields

Question 39

What are fields?

Answer 39

One point of data

Question 40

What is Syntax?

Answer 40

Grammar of a language

Question 41

Why is estimating a time scale for a project difficult? and how can this be accurately assessed?

Answer 41

It is difficult because there is no prior information to go on. You would need to break it down into smaller tasks and try them out.

Question 42

Does adding more people in a project resolve the problem faster?

Answer 42

Not always, it can potentially make it slower.

Question 43

What is a critical path when it comes to project management?

Answer 43

a critical path is the sequence of project network activities which add up to the longest overall duration, regardless if that longest duration has float or not. This determines the shortest time possible to complete the project. There can be ‘total float’ (unused time) within the critical path.

Question 44

What is a primary key?

Answer 44

Uniquely identifies a directory in a table.

Question 45

What is a foreign key?

Answer 45

Points to other records in other tables.

Question 46

What is Paramedic ethics?

Answer 46

Know a little and know when to ask