CNG257

What size key does the DES algorithm use?

56-bit

What is a digital signature?

A piece of encrypted data added to other data to verify the sender

Who issues certificates?

A private certificate authority

Which of the following encryption algorithms is a block cipher, and uses the Rijndael algorithm?

AES

Which of the following has three different key sizes that it can use?

AES

Which encryption algorithm uses a variable-length symmetric key?

Blowfish

What is the primary advantage of the DES encryption algorithm?

It is relatively fast.

Which of the following is the oldest known encryption method?

Caesar cipher

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

DES

Why is the XOR mathematical operation not secure?

It does not change the letter or word frequency.

An improvement on the Caesar cipher that uses more than one shift is called what?

Multi-alphabet substitution

Why is encryption an important part of security?

No matter how secure your network is, the data being transmitted is still vulnerable without encryption.

Which of the following is an encryption method developed by three mathematicians in the 1970s?

RSA

If you are using a block cipher to encrypt large amounts of data, which of the following would be the most important consideration when deciding which cipher to use (assuming all of your possible choices are well known and secure)?

Speed of the algorithm

What is the purpose of a certificate?

To validate the sender of a digital signature or software

Which of the following is the most common legitimate use for a password cracker?

Testing the encryption of your own network.

What type of encryption uses a different key to encrypt the message than it uses to decrypt the message?

Public key

Which of the following is the primary weakness in the Caesar cipher?

It does not disrupt letter frequency.

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

XOR