Encrypt the message \" HALT \" by translating the letters into numbers (via A=0,B=1,C=2,D=3,E=4,F=5,G=6,H=7,I=8, J=9,K=10,L=11,M=12,N=13,O=14,P=15,Q=16,R=17, S=18,T=19,U=20,V=21,W=22,X=23,Y=24,Z=25 ) and then applying the encryption function given, and then translating the numbers back into letters. (a) f(p)=(p+5) mod 26 _____________ (b) f(p)=(p+12) mod 26 _______________ (c) f(p)=(p+4) mod 26 ______________ Solution Encrypt message as : A=0,B=1,C=2,D=3,E=4,F=5,G=6,H=7,I=8, J=9,K=10,L=11,M=12,N=13,O=14,P=15,Q=16,R=17, S=18,T=19,U=20,V=21,W=22,X=23,Y=24,Z=25 and given encryption function :a) f(p)=(p+5)mod26 if p=Z=25 f(25)=(25+5)mod26 =30mod26=4 f(25)=E and f(p)=(p+5)mod26 if p=15 f(15)=(15+5)mod26 =20mod26=20 f(15)=U b) f(p)=(p+12)mod26 f(p)=(p+12)mod26 if p=Z=25 f(25)=(25+12)mod26 =37mod26=11 f(25)=L and for f(p)=(p+12)mod26 if p=15 f(15)=(15+12)mod26 =27mod26=1 f(15)=B c)f(p)=(p+4)mod26 f(p)=(p+4)mod26 if p=Z=25 f(25)=(25+4)mod26 =29mod26=3 f(25)=D and for f(p)=(p+4)mod26 if p=15 f(15)=(15+4)mod26 =19mod26=19 f(15)=T.