Question: Let (E,D) be a CPA-secure cipher defined over (K,M,C) and let H : M --> T be a collision-resistant hash function. Show that the following
Let (E,D) be a CPA-secure cipher defined over (K,M,C) and let H : M --> T be a collision-resistant hash function. Show that the following cipher is not AE-secure:
E1(k,m) = ( E(k,m) , H(m) ) = ( c1 , c2 )
D1( k , (c1,c2) ) = D(k,c1) , if H( D(k,c1 ) ) = c2
(reject), otherwise
Step by Step Solution
There are 3 Steps involved in it
1 Expert Approved Answer
Step: 1 Unlock
Question Has Been Solved by an Expert!
Get step-by-step solutions from verified subject matter experts
Step: 2 Unlock
Step: 3 Unlock
Study Help