Cryptography T/F
The "Base 26" cipher is actually just a multiplicative cipher with 26n possible keys where n represents the length of the keyword used for encoding
False
The Autokey cipher is a transposition cipher which uses a keyword followed by the beginning of the actual message in the encipherment process
False
The DES algorithm is an example of a public key encryption algorithm`
False
The Product of Primes method is the more efficient method for computing the greatest common divisor of numbers which are "large"
False
The playfair cipher is an example of a polygraphic substitution cipher which uses a 5x5 number block to encode/decode messages
False
We use combinations rather than permutations to determine the number of different ordered subsets which can be chosen from a larger group
False
A ciphertext obtained from the use of a polyalphabetic cipher will retain English Letter frequency
False
If A is not invertible in Z(26) then det(A)=0
False
Let gcd(a,b) = 1, then phi(a+b) = phi(a) + phi(b)
False
Matrices must be of equal size in order to multilply them
False
Polygraphic ciphers maintain English letter frequency upon encipherment
False
A Double Columnar Cipher is a transposition cipher which requires a keyword with a repeated letter
False
6 has no multiplicative inverse in Z(24)
True
A Hash Value must be sent immediately before an encrypted message in order to be effective
True
AN I.C. value close of .065 is indicative of a ciphertext which maintains English letter frequency and is monoalphabetic in nature
True
B34 (base 16) = 2868 (base 10)
True
Charles Babbage was able to crack the Vigenere Cipher but is sometimes not credited with the discovery since he failed to publish his work before others like Kasiski
True
Every matrix in the real numbers has an additive inverse
True
Hans-Thilo Schmidt sold secret Enigma information to foreign powers for personal and financial gains
True
In Z(16), 9 is its own multiplicative inverse
True
One requirement of a has function is that it must be "one way" This means that it must be extremely difficult to figure out the message given the hash value for that message
True
The Alberti Cipher was the first known polyalphabetic cipher to be developed
True
The Euclidean algorithm can be used to find the greatest common divisor of two positive integers and is based on the Division Algorithm?
True
The Friedman Test can be used to determine if a given cipher is monoalphabetic or polyalphabetic
True
The Hill Cipher can use any invertible matrix in Z(26) as a key
True
The Massey-Omura algorithm is an example of an asymmetric cipher
True
The RSA algorithm is a public key encryption algorithm which was developed by three men named Rivest, Shamir, and Adleman
True
The Running Key Cipher is actually just the Vigenere cipher but uses a passage from a predetermined book or paper as the "keyword"
True
The Sieve of Eratosthenes is a method which can be used to identify all prime numbers is a given set of posiive integers
True
The Vigenere Cipher is an example of a Polyalphabetic Cipher
True
The Vigenere square is actually just an addition modulo 26 table
True
The addition of matrices is commutative
True
The security of the RSA algorthim is based on the fact that very large numbers are difficult to factor
True
There are 26 different keys possible for a Shift Cipher
True
Three men, Diffie, Hellman, and Merkle, made significant achievements in the key distribution process
True
Transposition ciphers simply rearrange the letters of the plaintext and thus English letter frequency is maintained
True
Two events E and F are independent if, P(E and F) = P(E) * P(F)
True