Which one of the following are used to generate a message digest by the network security protocols?
(P) RSA
(Q) SHA-1
(R) DES
(S) MD5

Let the size of congestion window of a TCP connection be 32 KB when a timeout occurs. The round trip time of the connection is 100 msec and the maximum segment size used is 2 KB. The time taken (in msec) by the TCP connection to get back to 32 KB congestion window is __________.

An access sequence of cache block addresses is of length $$N$$ and contains $$n$$ unique block address. The number of unique block addresses between two consecutive accesses to the same block address is bounded above by $$k.$$ What is the miss ratio if the access sequence is passed through a cache of associativity $$A\, \ge \,k$$ exercising least-recently-used replacement policy?

Consider two processors ܲ$${P_1}$$ and $${P_2}$$ executing the same instruction set. Assume that under identical conditions, for the same input, a program running on $${P_2}$$ takes $$25$$% less time but incurs $$20$$% more $$CPI$$ (clock cycles per instruction) as compared to the program running on ܲ$${P_1}$$ If the clock frequency of ܲ$${P_1}$$ is $$1GHz,$$ then the clock frequency of $${P_2}$$ (in $$GHz$$) is _____________.