Exam 8: Random Bit Generation and Stream Ciphers

the longer the keyword the more difficult the cryptanalysis.

Examples of a pseudorandom function are decryption keys and nonces.

the best that can be done to determine if a PRNG generates numbers that have the characteristic of randomness is on the basis of multiple tests.these tests should seek to establish uniformity, scalability, and __________ .

the __________ is drawn from the physical environment of the computer and could include things such as keystroke timing patterns, disk electrical activity, mouse movements, and instantaneous values of the system clock.

__________ is a stream cipher designed in 1987 by Ron Rivest for RSA Security.

the purpose of the Maurer's universal statistical test is to determine whether the number of ones and zeros in a sequence are approximately the same as would be expected for a truly random sequence.

In a stream cipher structure a key is input to a pseudorandom bit generator that produces a stream of 8-bit numbers that are apparently random.the output of the generator, called a ___________ , is combined one byte at a time with the plaintext stream using the bitwise exclusive-OR operation.

two approaches that use a block cipher to build a PNRG and have gained widespread acceptance are:

A __________ is used to produce a pseudorandom string of bits of some fixed length.

the Linux operating system uses _________ entropy sources for generating random numbers.

An algorithm that is used to produce an open-ended sequence of bits is referred to as a ___________ .

the true random number generator may simply involve conversion of an analog source to a binary output.

A widely used technique for pseudorandom number generation is an algorithm known as the linear congruential method.

A pseudorandom number generator takes as input a fixed value called the __________ and produces a sequence of output bits using a deterministic algorithm.

the security of Blum, Blum, Shub is based on the difficulty of factoring n.

A stream of pseudorandom numbers should exhibit two forms of unpredictability: forward and __________ .

Various methods of modifying a bit stream to reduce or eliminate a bias have been develope D.these are referred to as ___________ algorithms.

A cryptographically secure pseudorandom bit generator is defined as one that passes the least significant bit test.

the distribution of bits in a random number sequence should be ___________ , therefore the frequency of occurrence of ones and zeros should be approximately equal.

A __________ takes as input a source that is effectively random.