According to the text, random numbers used in cryptography must be unpredictable. a. Why are statistically random numbers (which are often used in simulations) not sufficient for cryptographic...

According to the text, random numbers used in cryptography must be unpredictable.

a. Why are statistically random numbers (which are often used in simulations) not sufficient for cryptographic applications?

b. Suppose that the keystream generated by a stream cipher is predictable in the sense that if you are given n keystream bits, you can determine all subsequent keystream bits. Is this a practical security concern? Why or why not?