Trivium. Explain why warm-up phase is needed in Trivium and how Trivium achieves non-linarity. What is the first 5 bits (s₁, s₂, s₃, s₄, s₅) during the warm-up phase of Trivium if the IV and the key of Trivium each consist of 80 all-one bits. Note that these are only internal bits which are not used for encryption since the warm-up phase lasts for 1152 clock cycles.