watch -n .1 cat /proc/sys/kernel/random/entropy_avail While it is running, move your mouse, click your mouse, type somethings, read a large file, visit a website. You can also add to the list of activities. What activities increases the entropy significantly. Please describe your observation in your report.

To observe the behaviour, use the cat command to keep reading pseudo random numbers from /dev/random and pipe the output to hexdump for printing.

# cat /dev/random | hexdump Run the above command and see what happens if you do not move your mouse or type anything for around 20-30s. Now move your mouse or type something and observe what happens.

Now open a new terminal side by side and use the watch command to monitor the entropy. T hen repeat the same as above, first dont do any activity for 20-30s and then do some activity.

How many bits of entropy is required to generate a random number? Please describe and explain your observations. If a server uses /dev/random to generate the random session key with a client, describe how you can launch a Denial-Of-Service (DOS) attack on such a server.