Exam 8: Random Bit Generation and Stream Ciphers

With true random sequences each number is statistically independent of other numbers in the sequence and therefore unpredictable.

__________ algorithms are designed specifically and solely for the purpose of generating pseudorandom bit streams.

there are well-defined tests for determining uniform distribution and independence to validate that a sequence of numbers is random.

In key distribution and reciprocal authentication schemes two communicating parties cooperate by exchanging messages to distribute keys and/or authenticate each other.In many cases ___________ are used for handshaking to prevent replay attacks.

Random numbers play an important role in the use of encryption for various network security applications.

If the algorithm is good the resulting sequences will pass many reasonable tests of randomness.these numbers are referred to as ___________ numbers.

A source that is effectively random is referred to as __________ .

A fundamental requirement of the RSA public-key encryption scheme is the ability to generate _________ numbers.

the principle requirement of random or pseudorandom number generation is that the generated number stream be unpredictable.

A secret key for symmetric encryption that is generated for use for a short period of time is called a _________ .

typically the __________ takes as input a seed plus some context specific values such as a user ID or an application ID.

the stream cipher is similar to the one-time pad with a difference being that a one-time pad uses a pseudorandom number stream and a stream cipher uses a genuine random number stream.

the most important and widely used stream cipher is __________ .

A __________ uses a nondeterministic source to produce randomness.

the seed that serves as input to the PRNG must be secure for cryptographic applications.

two distinct requirements for a sequence of random numbers are unpredictability and __________ .

two criteria used to validate that a sequence of numbers is random are uniform distribution and __________ .

the Blum, Blum, Shub generator is referred to as a ____________ .

the purpose of the __________ test is to determine whether the number of runs of ones and zeros of various lengths is as expected for a random sequence.

three broad categories of cryptographic algorithms are commonly used to create PRNGs: symmetric block ciphers, asymmetric ciphers, and hash functions and message authentication codes.