A
select 2 prime number p&q
calculate n= pq (publick key given to B).
choose a nother number E(also pulic) relatively prime to (p-1)(q-1)
A wants to decode C
it findes anumber D such that ED=1 mod (d-1)(q-1)
calculate:C mode N
B
given amessage M,B encrypts M to cipher code C whereC=ME mod N
B sends C to A
two number are relatively prim if they have no common factor other than 1