Question

Question 1

A hash function takes a ____________ length input and returns a _________ length output

variable / fixed

fixed / variable

variable / variable

fixed / fixed

Question 2

What is the one way property of cryptographic hash functions? h:hash value, M: message

easy to compute h from f(M)

easy to compute M from h

hard to compute h from f(M)

simple structure of the function f

Question 3

There're two type of collision resistance : weak and strong

True

False

Question 4

In most operating systems, a hash value of the password (or pass phrase) is used for the password authentication

True

False

Question 5

______________ means it is hard to find 2 messages what will produce the same hash value

Weak collision resistence

Strong collision resistence

Merkle-Damgard construction

Davis-Mayer structure

Question 6

What is the probability that, at least, two of 50 students in a classroom have the same birthday?

70%

90%

94%

99%

Question 7

If you could factorize a large prime number fast, you can find the private key {e} of RSA because {e} is a prime factor

True

False

Question 8

'Salt' value is a short string data appended to the users' password.

True

False

Question 9

salt value has be unique per user

True

False

Question 10

Modern UNIX operating systems store the hash value of your password in /etc/passwd

True

False

Answer 1

Question 1

A hash function takes a ____________ length input and returns a _________ length output

Answer: variable / fixed

2. What is the one way property of cryptographic hash functions? h:hash value, M: message

easy to compute h from f(M)

3. There're two type of collision resistance : weak and strong

True

4.In most operating systems, a hash value of the password (or pass phrase) is used for the password authentication

True

5. _____________ means it is hard to find 2 messages what will produce the same hash value
Strong collision resistence

6.What is the probability that, at least, two of 50 students in a classroom have the same birthday?

99%

7.If you could factorize a large prime number fast, you can find the private key {e} of RSA because {e} is a prime factor

False

Question 8

'Salt' value is a short string data appended to the users' password.

True

Question 9

salt value has be unique per user

True

Question 10

Modern UNIX operating systems store the hash value of your password in /etc/passwd

True