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Software for maintaining an on-the-fly-encrypted volume. Data is automatically encrypted right before it is saved, then decrypted right after it is loaded, all w/o user intervention.
_____ uses at least two different shifts, changing the shift with different letters in the plain text.
Which of the following encryption algorithms relies on the inability to factor large prime numbers?
A symmetric Stream Cipher published by the German engineering firm Seimans in 1993. A software based stream cipher that uses a Lagged Fibonacci generator along with concepts borrowed from shrinking generator ciphers.
The mode makes a block cipher into a synchronous stream cipher. It generates keystream blocks, which are then XORed with the plaintext blocks to get the ciphertext.
As a network administrator, you have implemented WPA2 encryption in your corporate wireless network. The WPA2's ________ integrity check mechanism provides security against a replay attack.
Early attempt to make substitution ciphers more robust, masks letter frequencies, plain text letters map to multiple cipher text symbols.
If Bob is using asymmetric cryptography and wants to send a message to Alice so that only she can decrypt it, what key should he use to encrypt the message?
A transposition cipher invented 1918 by Fritz Nebel, used a 36 letter alphabet and a modified Polybius square with a single columnar transposition.
Symmetric algorithm. Designed by James Massey and Xuejia Lai. Operates on 64 bit blocks and has a 128 bit key. Consists of 8 identical transformations each round and an output transformation.
This algorithm was published by the German engineering firm Seimans in 1993. It is a software based stream cipher using Lagged Fibonacci generator along with a concept borrowed from the shrinking generator ciphers.
Which component of IPsec performs protocol-level functions that are required to encrypt and decrypt the packets?
Juanita has been assigned the task of selecting email encryption for the staff of the insurance company she works for. The various employees often use diverse email clients. Which of the following methods is available as an add-in for most email clients?
Nicholas is working at a bank in Germany. He is looking at German standards for pseudo random number generators. He wants a good PRNG for generating symmetric keys. The German Federal Office for Information Security (BSI) has established four criteria for quality of random number generators. Which ones can be used for cryptography?
Which one of the following are characteristics of a hash function? (Choose two)
____________cryptography uses one key to encrypt a message and a different key to decrypt it.
Widely used, particularly with Microsoft operating systems. Created by MIT and derives its name from the mythical three headed dog. The is a great deal of verification for the tickets and the tickets expire quickly. Client authenticates to the Authentication Server once using a long term shared secret and receives back a Ticket-Granting Server. Client can reuse this ticket to get additional tickets without reusing the shared secret. These tickets are used to prove authentication to the Service Server.
Basic information theory is the basis for modern symmetric ciphers. Understanding the terminology of information theory is, therefore, important. If a single change of a single bit in the plaintext causes changes in all the bits of the resulting ciphertext, what is this called?
John is responsible for VPNs at his company. He is using IPSec because it has two different modes. He can choose the mode appropriate for a given situation. What are the two modes of IPSec? (Choose two)
Uses a formula, M_n = 2^n ? 1 where n is a prime number, to generate primes. Works for 2, 3, 5, 7 but fails on 11 and on many other n values.
What is the name of the attack where the attacker obtains the ciphertexts corresponding to a set of plaintexts of his own choosing?
The art and science of writing hidden messages so that no one suspects the existence of the message, a type of security through obscurity. Message can be hidden in picture or audio file for example. Uses least significant bits in a file to store data.
Which of the following is a fundamental principle of cryptography that holds that the algorithm can be publicly disclosed without damaging security?
This is a 128 bit hash that is specified by RFC 1321. It was designed by Ron Rivest in 1991 to replace an earlier hash function.
Which one of the following best describes a process that splits the block of plaintext into two separate blocks, then applies the round function to one half, and finally swaps the two halves?
Which of the following is used to encrypt email and create digital signatures?
This hash function uses 512-bit blocks and implements preset constants that change after each repetition. Each block is hashed into a 256-bit block through four branches that divides each 512 block into sixteen 32-bit words that are further encrypted and rearranged.
A method for cracking modern cryptography. The attacker obtains the cipher texts corresponding to a set of plain texts of own choosing. Allows the attacker to attempt to derive the key. Difficult but not impossible.
When learning algorithms, such as RSA, it is important to understand the mathematics being used. In RSA, the number of positive integers less than or equal to some number is critical in key generation. The number of positive integers less than or equal to n that are coprime to n is called ______.
Hash. Created by Ronald Rivest. Replaced MD4. 128 bit output size, 512 bit block size, 32 bit word size, 64 rounds. Infamously compromised by Flame malware in 2012.
In IPSec, if the VPN is a gateway-gateway or a host-gateway, then which one of the following is true?
A simple algorithm that will take the initial key and from that generate a slightly different key each round.
Ferris has been assigned the task of selecting security for his company's wireless network. It is important that he pick the strongest form of wireless security. Which one of the following is the strongest wireless security?
A protocol for key aggreement based on Diffie-Hellman. Created in 1995. Incorporated into the public key standard IEEE P1363.
Cryptographic hashes are often used for message integrity and password storage. It is important to understand the common properties of all cryptographic hashes. What is not true about a hash?
In a Feistel cipher, the two halves of the block are swapped in each round. What does this provide?
Frank is trying to break into an encrypted file… He is attempting all the possible keys that could be used for this algorithm. Attempting to crack encryption by simply trying as many randomly generated keys as possible is referred to as what?
Which service in a PKI will vouch for the identity of an individual or company?
Jane is looking for an algorithm to ensure message integrity. Which of following would be an acceptable choice?
Changes to one character in the plain text affect multiple characters in the cipher text, unlike in historical algorithms where each plain text character only affect one cipher text character.
TESTED 08 Dec 2024