Well, d is an EC point hashed to an integer. So it can be implemented this way:

d=hash(A*c)=hash(C*a)
E=B+G*d
e=b+d

Here, hash is any hash function, and G is the base point.
Alternatively, a different key derivation function can be used:

E=B*d
e=b*d

I hope it's clearer now.