27. Which of the following characteristics is not of a good stream cipher?

Вариант ответа 1 - A. Long periods of no repeating patterns.

Вариант ответа 2 - B. Statistically predictable.

Вариант ответа 3 - C. Keystream is not linearly related to the key.

Вариант ответа 4 - D. Statistically unbiased keystream.