5.6 For each of the following modifications to the Merkle Damgrd trans- form (Construction 5.3), determine whether the result is collision resis- tant. Iif yes, provid proof if nodt, dkamonstrate an attaci. (a) Modify the construction so that the input length is not included at all (i.e., output zB and not zB+1 hs(4pllL)). (Assume the resulting hash function is only defined for inputs whose length is an integer multiple of the block length.) (b) Modify the construction so that instead ofoutputtingz=h"(zBIL), the algorithm outputs zBL 5.6 For each of the following modifications to the Merkle Damgrd trans- form (Construction 5.3), determine whether the result is collision resis- tant. Iif yes, provid proof if nodt, dkamonstrate an attaci. (a) Modify the construction so that the input length is not included at all (i.e., output zB and not zB+1 hs(4pllL)). (Assume the resulting hash function is only defined for inputs whose length is an integer multiple of the block length.) (b) Modify the construction so that instead ofoutputtingz=h"(zBIL), the algorithm outputs zBL