Someone to answer please. Thank you

If not, explain why encryption is not necessary. If yes, what and whose key is used? and explain why encryption is necessary. (3 pts) 10. If a message digest is defined as h(m) (m+ 1234)%9876543. Is this strong message digest? If yes, explain. If not, give two values of m that produce the same hash. (5 points) 11. If it has become feasible to use brutal force solution to try up to 2200 random messages and to obtain identical message digests, how many bits should the output of a message digest algorithm must be in order to remain secure? (5 points)