Chapter 8 End of Book Questions CSCI 290

Which of the following methods uses a variable-length symmetric key?

A Blowfish

Which of the following most accurately defines encryption?

A Changing a message so it can only be easily read by the intended recipient.

Why is binary mathematical encryption not secure?

A It does not change letter or word frequency

What advantage does a symmetric key system using 64-bit blocks have?

A It is fast

Which of the following is used by PPTP to encrypt packets?

A Microsoft Point-to-Point Encryption

Which of the following is most true regarding new encryption methods?

A Never use them until they have been proven

Which of the following is the oldest protocol used by VPN?

A PPTP

What is PGP?

A Pretty Good Privacy, a public key encription method

Which of the following is most true regarding binary operations and encryption?

B They can form a part of viable encryption methods

Which of the following is a symmetric key system using 64-bit blocks?

B DES

What type of encryption uses different keys to encrypt and decrypt the message?

B Public key

What size key does a DES system use?

C 56 bit

Which of the following is the oldest encryption method discussed in this text?

C Caesar Cipher

Which of the following is an encryption method using two or more different shifts?

C DES

Which of the following is most likely to be true of an encryption method advertised as unbreakable?

C It is likely to be exaggerated

Which binary mathematical operation can be used for a simple encryption method?

C XOR

What should you be most careful of when looking for an encryption method to use?

D How long the algorithm has been around

What is the main problem with simple substitution?

D It maintains letter and word frequency

Which of the following methods is available as an add-in for most e-mail clients?

D PGP

Which of the following is most true regarding certified encryption methods?

D There is no such thing as certified encryption