Suppose you have a block cipher Ek(x) that has 256 bits of security. Now consider a new cipher which is the original cipher composed with itself using independent keys.

Ek1,k2(x)=Ek1Ek2(x)

How many bits of security does the new cipher E have? Why?

Previous Problem Problem List Next Problem Suppose you have a block cipher Ex(x) that has 256 bits of security. Now consider a new cipher which is the original cipher composed with itself using independent keys. Eki kz ,(x) = Ek, Ek, (x) = o How many bits of security does the new cipher E' have? Why