VMPC Stream Cipher.
Bartosz Zoltak · IACR Cryptology ePrint Archive · 2003
The VMPC function is a combination of triple permutation composition and integer addition. It differs from a simple triple permutation composition with one integer addition operation performed on some of the elements of the permutation. The consequence of this addition operation is corruption of cycle structure of the transformed permutation the fundamental source of the function's resistance to inverting.