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OSI and TCP/IP model

1. Choose all right statements:
A) A principal concept in both the OSI and TCP/IP model is layering.
B) A principal concept in both the OSI and TCP/IP model is controlling.
C) Layering is a structuring technique to manage complexity and evolution.
D) Controlling is a structuring technique to manage complexity and evolution.
E) None of the above.

2. There are core aspects or properties to security: Choose all right statements:
A) Confidentiality: Accessed only by authorized parties
B) Availability: Accessible to unauthorized parties at appropriate time
C) Integrity: Modified by unauthorized parties only in authorized ways
D) Availability: Accessible to authorized parties at appropriate time
E) None of the above.

3. Choose all right statements:
A) Authenticity: A message is genuine but from unauthorized parties.
B) Accountability: Availability of an action to the party that is responsible for causing it.
C) Authenticity is considered a dimension of confidentiality, since the definition of confidentiality permits changes to information only by authorized parties.
D) Accountability: Confidentiality of an action to the party that is not responsible for causing

4. Choose all right statements:
A) The Three Ds of Security are deterrences, detections, and defensive controls.
B) Deterrenc is the first mode of security since it “reduces the likelihood of security compromise”
C) Detection is the second mode of security since it “reduces the frequency of security compromises”.
D) Examples of defensive control mechanisms are virus filters, firewalls, spam filters, router access lists, and static routes.
E) None of the above.

Cryptography Fundamentals. Public-Key Cryptography and Message Authentication
5. The two methods of encrypting data are
A) Substitution and transposition
B) Block and stream
C) Symmetric and asymmetric
D) DES and AES
6. The only cipher system said to be unbreakable by brute force is
A) AES
B) DES
C) One-time pad
D) Triple DES

7. When a user needs to provide message integrity, what options may be the best?
A) Send a digital signature of the message to the recipient
B) Encrypt the message with a symmetric algorithm and send it
C) Create a checksum, append it to the message, encrypt the message, then send it to the recipient
D) Encrypt the message with a private key so the recipient can decrypt with the corresponding public key
8. Consider the following protocol that involves both RSA public-key operations and DES. Suppose that A has an RSA private key prv(A) and an RSA public key pub(A). Suppose that B has an RSA private key prv(B) and an RSA public key pub(B). Assume both A and B knows each other’s public key. A wants to send B some message M. A selects random DES key K and send B the following two messages:
— Epub(B)( K, Sigprv(A)(K))
— EK(M)

4. Choose all right statements:
A) The Three Ds of Security are deterrences, detections, and defensive controls.
B) Deterrenc is the first mode of security since it “reduces the likelihood of security compromise”
C) Detection is the second mode of security since it “reduces the frequency of security compromises”.
D) Examples of defensive control mechanisms are virus filters, firewalls, spam filters, router access lists, and static routes.
E) None of the above.

Cryptography Fundamentals. Public-Key Cryptography and Message Authentication
5. The two methods of encrypting data are
A) Substitution and transposition
B) Block and stream
C) Symmetric and asymmetric
D) DES and AES
6. The only cipher system said to be unbreakable by brute force is
A) AES
B) DES
C) One-time pad
D) Triple DES

7. When a user needs to provide message integrity, what options may be the best?
A) Send a digital signature of the message to the recipient
B) Encrypt the message with a symmetric algorithm and send it
C) Create a checksum, append it to the message, encrypt the message, then send it to the recipient
D) Encrypt the message with a private key so the recipient can decrypt with the corresponding public key
8. Consider the following protocol that involves both RSA public-key operations and DES. Suppose that A has an RSA private key prv(A) and an RSA public key pub(A). Suppose that B has an RSA private key prv(B) and an RSA public key pub(B). Assume both A and B knows each other’s public key. A wants to send B some message M. A selects random DES key K and send B the following two messages:
— Epub(B)( K, Sigprv(A)(K))
— EK(M)