Fall 2001, CSE 597E: Quiz 4 and solution - 7 Nov 2001


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  1. [2 point]What is a pseudorandom number generator? (only one answer, please)

    1. A program that generates a sequence of pseudo numbers, i.e. rational numbers that approximate real numbers
    2. A program which generates a sequence of numbers having the appearance of randomness, but nevertheless following a specific, deterministic algorithm.
    3. A program which generates numbers with a pseudo-uniform probabilistic distribution
    4. A nondeterministic program (pseudo-program) which generates numbers in a completely rand omized way.

  2. [4 points] Pseudorandom generators are used in security protocols for (mark all correct answers)

    1. Nonces
    2. Session keys
    3. Assigning an identity to the attackers
    4. Parameters in digital signatures

  3. [2 points]Which of the following is a characteristic of linear congruential ge nerators (only one answer, please)

    1. They are based on physical processes instead of programs
    2. The next number in the sequence is always greater than previous number
    3. The next number in the sequence is computed by using previous number
    4. They generate a linear sequence, i.e. numbers are never repeated (no loops).

  4. [2 points]Which of the following is a characteristic of true random number gen erators (only one answer, please)

    1. They generate a monotonic sequence of numbers (in increasing order)
    2. They generate more numbers than the pseudorandom number generators
    3. They are more subject to attacks than the pseudorandom number generators
    4. They are based on physical processes instead of programs