Bruce Schneier is a well-known and highly respected cryptographer. He has developed several pseudo random number generators as well as worked on teams developing symmetric ciphers. Which one of the following is a symmetric block cipher designed in 1993 by Bruce Schneier team that is unpatented?
Answer(s): B
Blowfish https://en.wikipedia.org/wiki/Blowfish_(cipher)Blowfish is a symmetric-key block cipher, designed in 1993 by Bruce Schneier and included in many cipher suites and encryption products.
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.
Answer(s): D
VeraCrypt https://en.wikipedia.org/wiki/VeraCryptVeraCrypt is a source-available freeware utility used for on-the-fly encryption (OTFE). It can create a virtual encrypted disk within a file or encrypt a partition or (in Windows) the entire storage device with pre-boot authentication.Incorrect answers:PGP - designed by Phil Zimmerman as a freeware e-mail security program and was released in 1991. It was the first widespread public key encryption program. VPN - A virtual private network (VPN) extends a private network across a public network and enables users to send and receive data across shared or public networks as if their computing devices were directly connected to the private network. Applications running across a VPN may therefore benefit from the functionality, security, and management of the private network. Encryption is a common, although not an inherent, part of a VPN connectionCryptool - an open-source project that focuses on the free e-learning software CrypTool illustrating cryptographic and cryptanalytic concepts. According to "Hakin9", CrypTool is worldwide the most widespread e-learning software in the field of cryptology.
Which of the following statements is most true regarding binary operations and encryption?
Answer(s): C
They can form a part of viable encryption methods for example - https://en.wikipedia.org/wiki/XOR_cipherThe XOR operator is extremely common as a component in more complex ciphers. By itself, using a constant repeating key, a simple XOR cipher can trivially be broken using frequency analysis. If the content of any message can be guessed or otherwise known then the key can be revealed. Its primary merit is that it is simple to implement, and that the XOR operation is computationally inexpensive. A simple repeating XOR (i.e. using the same key for xor operation on the whole data) cipher is therefore sometimes used for hiding information in cases where no particular security is required. The XOR cipher is often used in computer malware to make reverse engineering more difficult.
Which of the following is generally true about key sizes?
Answer(s): A
Larger key sizes increase security https://en.wikipedia.org/wiki/Key_sizeKey length defines the upper-bound on an algorithm's security (i.e. a logarithmic measure of the fastest known attack against an algorithm), since the security of all algorithms can be violated by brute-force attacks. Ideally, the lower-bound on an algorithm's security is by design equal to the key length (that is, the security is determined entirely by the keylength, or in other words, the algorithm's design doesn't detract from the degree of security inherent in the key length). Indeed, most symmetric-key algorithms are designed to have security equal to their key length. However, after design, a new attack might be discovered. For instance, Triple DES was designed to have a 168 bit key, but an attack of complexity 2112 is now known (i.e. Triple DES now only has 112 bits of security, and of the 168 bits in the key the attack has rendered 56 'ineffective' towards security). Nevertheless, as long as the security (understood as 'the amount of effort it would take to gain access') is sufficient for a particular application, then it doesn't matter if key length and security coincide. This is important for asymmetric-key algorithms, because no such algorithm is known to satisfy this property; elliptic curve cryptography comes the closest with an effective security of roughly half its key length.
The next number is derived from adding together the prior two numbers (1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89).
Fibonacci Sequence https://en.wikipedia.org/wiki/Fibonacci_numberIn mathematics, the Fibonacci numbers, commonly denoted Fn, form a sequence, called the Fibonacci sequence, such that each number is the sum of the two preceding ones, starting from 0 and 1. That is,F0 = 0, F1=1, Fn = Fn-1 + Fn-2; for n > 1.The beginning of the sequence is thus:0,1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144...Incorrect answers:Prime numbers - numbers that have only 2 factors: 1 and themselves. 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47...Fermat numbers - a positive integer of the form Fn = 2^2^n +1; where n is a non-negative integer. The first few Fermat numbers are: 3, 5, 17, 257, 65537, 4294967297, 18446744073709551617, ... Odd numbers - any number which cannot be divided by two 1, 3, 5, 7, 9, 11, 13, 15 ...
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