CMIN 244 MidTerm [Chapter 6]
What size key does this system use? a. 56bit b. 128big c. 64bit d. 255bit
56bit
What is a digital signature? a. A piece of encrypted data added to other data to verify the sender b. A scanned-in version of your signature, often in .jpg format c. A signature that is entered via a digital pad or other device d. A method for verifying the recipient of a document
A piece of encrypted data added to other data to verify the sender
Which is a block cipher developed by Belgian researchers and providing 128-, 192-, and 256-bit key sizes? a. RSA b. Blowfish c. AES d. DES3
Blowfish
Which is a symmetric block cipher developed in 1993 that provides variable-length key sizes ranging from 32 to 448 bits? a. IDEA b. DES3 c. AES d. Blowfish
Blowfish
An improvement on the Caesar cipher that uses more than one shift is called a what? a. Multi-alphabet substitution b. Triple DES c. DES encryption d. IDEA
Multi-alphabet substitution
Operations not found in normal math that can be performed on binary numbers include all of the following EXCEPT: a. XOR b. AND c. OR d. NOT
NOT
Which is a widely used public key system that is considered by many experts to be very secure and is available as a plug-in for Netscape Messenger, MSN Messenger, and other communication software? a. AES b. Blowfish c. IDEA d. PGP
PGP
What type of encryption uses a different key to encrypt the message than it uses to decrypt the message? a. Symmetric b. Public key c. secure d. Private key
Public key
Which of the following is an encryption method developed by three mathematicians in the 1970s? a. DES b. RSA c. DSA d. PGP
RSA
Which of the following is the most common legitimate use for a password cracker? a. Military intelligence agents using it to break enemy communications b. Trying to break the communications of criminal organizations in order to gather evidence c. There is no legitimate use for a password cracker d. Testing the encryption of your own network
Testing he encryption of your own network
Which is a weakness of Data Encryption Standard? a. Throughput is minimal, making it a poor choice for large files. b. It is based on a 1970s era block cipher. c. It's complexity in scrambling text makes it very processor-intensive and slow. d. The key must be transmitted, thus risking it being compromised.
The key must be transmitted, thus risking it being compromised
Many encryption techniques such as XOR are easily broken because: a. Their basis in binary numbers makes them easy targets for math processors b. Their public keys are readily available c. Brute force techniques can break them d. The underlying letter and word frequency can still be determined
The underlying letter and word frequency can still be determined
What is the purpose of a certificate? a. To validate the recipient of a document b. To verify that software is virus free c. To guarantee that a signature is valid d. To validate the sender of a digital signature or software
To validate the sender of a digital signature or software
Which is NOT a part of a step in the XOR operation of encryption method. a. Convert message text to ASCII b. Convert ASCII to binary c. XOR ASCII with a key d. XOR binary numbers with a key
XOR ASCII with a key
Which is NOT an encryption method? a. PGP b. AES c. ASCII d. DES
ASCII
Which is a very early encryption method? a. WEP b. Caesar cipher c. DES3 d. AES
Caesar cipher
Which type of encrypted communication is most common? a. Computer and Internet communications b. Radio communications c. Written documents d. Telephone conversations
Computer and Internet communications
Which of the following is a symmetric key system using blocks? a. PGP b. DES c. Blowfish d. RSA
DES
Which is a powerful password cracker that works on Windows and Linux platforms? a. John the Ripper b. Brutus c. Solarwinds d. Quantum Cracker
John the Ripper
Attempting to determine a password by simply trying every possible combination within the set parameters until successful is called: a. password recovery b. authentication auditing c. brute force d. password cracking
brute force